Abbreviated Forms: Abbreviations, Acronyms, Initialisms

The New Shorter Oxford English Dictionary

The New Shorter Oxford English Dictionary based on historical principles. 1993.

Abbreviation (noun, late Middle English [1350-1469])
†. LME.
b esp. A shortened form of a word, phrase, or symbol. (Late 16th century [1570-1599])
2. The action of abbreviating. (Mid 16th century [1530-1569])
Acronym (nour & verb, mid 20th century [1930-1969])
A n. A word formed from the initial letters or parts of other words; loosely an abbreviation composed of initial letters. (Mid 20th century [1930-1969])
B v.t. Abbreviate as an acronym. (Mid 20th century [1930-1969])
Initialism (noun, late 19th century [1870-1899])
A group of initial letters used as an abbreviation, esp. one in which each letter is pronounced separately (cf. acronym); the use of such initials.

Glossary of Linguistic Terms

By SIL International. Online:

No entries for abbreviation, acronym or initialism.

Lexicon of Linguistics

Online: (University of Utrecht, The Netherlands).

Acronym (morphology)
a word composed of the initial characters of other words. EXAMPLE: the English acronyms NATO, FOP and FEC are made out of North Atlantic Treaty Organization, First Order Principle and Free Element Condition, respectively. Some Dutch examples are: TROS, KNAV and DAF.
Contraction (syntax)
the phenomenon that two or more elements are pronounced as one. EXAMPLE: ain't is a contraction of is not, wanna of want to. See wanna-contraction.

No entires for abbreviation and initalism.

Oxford English Reference Dictionary

Oxford English Reference Dictionary. 2nd edition, 1996. (192.000 entries and definitions)

1. an abbreviated form, esp. a shorthand form of a word or phrase.
2. the process or result of abbreviating.
a word, usu. pronounced as such, formed from the initial letters of other words (e.g. Ernie, laser, Nato) (cf. initialism).
4. a. a shortening of a word by combination or elision;
4. b. a contracted word or group of words.
a group of initial letters used as an abbreviation for a name or expression, each letter being pronounced separately (e.g. BBC).

The DK Illustrated Oxford Dictionary (1998; 187.000 entries and definitions) uses the same definitions for abbreviation and acronym but has no entry for initialism.

Oxford Advanced Learner's Dictionary

Oxford Advanced Learner's Dictionary of Current English. 4th edition, 1989.

abbreviation (noun)
1. abbreviating; being abbreviated.
2. shortened form of a word, phrase, etc.: 'Sept' is an abbreviation for 'September'. 'GB' is the abbreviation of/for 'Great Britain'.
acronym (noun)
word formed from the initial letters of a group of words, eg UNESCO, ie United Nations Educational, Scientific and Cultural Organization.
contraction (noun)
3. shortened from of a word: ‘Can't’ is a contraction of ‘cannot’.

Collins COBUILD English Dictionary for Advanced Learners

Collins COBUILD English Dictionary for Advanced Learners. 3rd edition, 2001.

An abbreviation is a short form of a word or phrase, made by leaving out some of the letters or by using only the first letter of each word. The postal abbreviation for Kansas is KS.
An acronym is a word composed of the first letters of the words in a phrase, especially when this is used as a name. An example of an acronym is NATO which is made up of the first letters of ‘North Atlantic Treaty Organization’.
2. A contraction is a shorthand form of a word or words. “It's” (with an apostrophe) should be used only as a contraction for it is.

Chambers 21st Century Dictionary

Online version:

abbreviation (noun)
1. a shortening of a word written instead of a whole word eg approx. for approximately. Compare acronym, contraction, initialism.
2. the act or process of abbreviating something, or the result of this.
acronym (noun) [etymology: 1940s: from Greek akron point or tip + onyma name.]
a word made from the first letters or syllables of other words, and usually pronounced as a word in its own right, eg NATO. Compare abbreviation, contraction, initialism.
contraction (noun)
1. the process of contracting or state of being contracted.
2. a decrease in length, size or volume.
3. a tightening of the muscles caused by a shortening in length of the muscle fibres.
4. (contractions) the regular painful spasms of the muscles of the uterus that occur during labour.
5. a shortened form of a word or phrase which includes at least the last letter of the word or phrase. 'Aren't' is a contraction of 'are not'.
initialism (noun)
1. Brit a set of initial, usually capital, letters used as an abbreviation, especially of an organization, where each letter is given its own separate pronunciation, eg 'BBC' for British Broadcasting Corporation or 'FBI' for Federal Bureau of Investigation.
2. US an acronym.

Newbury House Dictionary of American English


acronym (noun)
a word formed from the first letters or parts of other words: "SCUBA" is an acronym for "self-contained underwater breathing apparatus."
contraction (noun)
1. a shortened word or words, as in “can't” for cannot and “I'm” for “I am”.

No entries for abbreviation or initialism.

Webster's Online Dictionary - The Rosetta Edition™

Online: Based on other dictionaries and sources; definitions are borrowed from WordNet.


Merriam-Webster Online Dictionary:

1. the act or result of abbreviating : ABRIDGMENT
2. a shortened form of a written word or phrase used in place of the whole <amt is an abbreviation for amount>
a word (as NATO, radar, or snafu) formed from the initial letter or letters of each of the successive parts or major parts of a compound term;
also: an abbreviation (as FBI) formed from initial letters
2. a shortening of a word, syllable, or word by omission of a sound or letter;
also: a form produced by such shortening
an acronym formed from initial letters

Compact Oxford English Dictionary

Online version:

abbreviation (noun)
1. a shortened form of a word or phrase.
2. the process or result of abbreviating.
acronym (noun) [ORIGIN from Greek akron 'end, tip' + onoma 'name'.]
a word formed from the initial letters of other words (e.g. laser, Aids).
contraction (noun)
3. a word or group of words resulting from contracting an original form.
initialism (noun)
an abbreviation consisting of initial letters pronounced separately (e.g. BBC).

American Heritage Dictionary of the English Language

The American Heritage® Dictionary of the English Language: Fourth Edition. 2000. Accessible online through

1. The act or product of shortening.
2. A shortened form of a word or phrase used chiefly in writing to represent the complete form, such as Mass. for Massachusetts or USMC for United States Marine Corps.
A word formed from the initial letters of a name, such as WAC for Women's Army Corps, or by combining initial letters or parts of a series of words, such as radar for radio detecting and ranging.
contraction (noun)
2.a. A word, as won't from will not, or phrase, as o'clock from of the clock, formed by omitting or combining some of the sounds of a longer phrase.
2.b. The formation of such a word.
An abbreviation consisting of the first letter or letters of words in a phrase (for example, IRS for Internal Revenue Service), syllables or components of a word (TNT for trinitrotoluene), or a combination of words and syllables (ESP for extrasensory perception) and pronounced by spelling out the letters one by one rather than as a solid word.

Duden Deutsches Universalwörterbuch

2., völlig neu bearbeitete und stark erweiterte Ausgabe. Mannheim: Dudenverlag, 1989.

Abkürzung, die; -; -en:
1. das Abkürzen, Verkürzen.
2. eine Entfernung, Wegstrecke abkürzender Weg: eine A. kennen, nehmen.
3. abgekürztes Wort; Abk.: Abk.
Akronym, das; -s, -e:
Buchstabenwort, das <Pl. …wörter>
Kurzwort, das aus den Anfangsbuchstaben mehrerer Wörter gebildet ist; Akronym; Initialwort (z.B. UNO)
Initialwort, das <Pl. …wörter> (Sprachw.)
Kurzwort, das <Pl. …wörter> (Sprachw.)
Wort, das aus Bestandteilen eines od. mehrerer Wörter gebildet ist (z.B. "Kripo" aus Kriminalpolizei).

Van Dale Groot Woordenboek der Nederlandse Taal

Dertiende, herziene uitgave. Utrecht: Van Dale, 1999.

abbreviatie (de (v.); vgl. -atie) [1548 <Lat. abbreviatio (verkorten)>]
acroniem (het; vgl. -niem) [na 1950 gevormd van Gr. akros (úitstekende) + niem]
letterwoord; - (comp.) afkorting of letterreeks ter vervanging van een veelgebruikte verbinding of formule in de communicatie, m.n. in nieuwsgroepen (b.v. ASAP voor 'as soon as possible' en CU voor 'see you').
afkorting (de (v.); vgl. -ing)
1. het afkorten of afgekort-worden
2. (gew.) het verminderen van een rekening, een loon enz., syn. mindering: iets op afkorting betalen, in mindering
3. afgekort woord of woorddeel, verkorte uitdrukking gevormd door de eerste letter of letters van het woord, gevolgd door een punt, of door een bepaald teken, syn. abbreviatie, abbreviatuur, breviatuur, verkorting: in advertenties leest men vaak de afkorting z.b.b.h.h. = zijn bezigheden buitenshuis hebbende; enz. is de afkorting van 'enzovoorts', etc. van 'etcetera'.
letterwoord (het)
woord gevormd uit de beginletters van een aantal samenhorende woorden (m.n. van delen van een naam), syn. acroniem, initiaalwoord: 'vip' is een letterwoord gevormd uit 'very important person'.


Website van de Nederlandse Taalunie:

Zie Afkortingen: functie en vorm (algemeen).

Le petit Robert

Le nouveau petit Robert. Dictionnaire alphabétique et analogique de la langue française. Paris: Dictionnaires Le Robert, 2004.

abréviation [n.f.v. 1450; «texte abrégé» 1375; bas lat. abbreviatio] ⇒ acronyme, aphérèse, apocope, sigle
1. Abrégement (de temps).
2. Retranchement de lettres dans un mot, de mots dans une phrase pour écrire plus vite ou prendre moins de place. Abréviation de Mademoiselle en Mlle, de kilomère en km, de c'est-à-dire en c.-à-d.
Mot écrit en abrégé. L'abréviation se prononce toujours comme le mot entier. Liste des abréviations.
3. par ext. Expression, mot abrégé à l'oral.
acronyme [n.m. – 1968; angl. acronym «mot formé d'initiales ou de syllabes de plusieurs mots», de acro- et -onym «nom», d'apr. homonym]
ling. Sigle prononcé comme un mot ordinaire. «Ovni» et «sida» sont des acronymes.
Mot formé de syllabes de mots différents. ⇒mot-valise. Acronymes anglais utilisés en français (ex. sonar).
aphérèse [n.f. – 1701; aph(a)eresis 1521; lat. gramm. d'o. gr. aphaeresis]
ling. Chute d'un phonème ou d'un groupe de phonèmes au début d'un mot (opposé à apocope). ⇒troncation. «Car» pour «autocar» se dit aphérèse.
apocope [n.f. – 1521; lat. gramm. d'o. gr. apocopa]
ling. Chute d'un phonème, d'une ou plusieurs syllabes à la find d'un mot (opposé à aphérèse). ⇒troncation. On dit «télé» pour «télévision», «mat» pour «matin» par apocope.
sigle [n.m. – 1721; lat. jurid. sigla «signes abréviatifs»]
1. hist. Initiale servant d'abréviation. Les sigles des manuscrits anciens.
2. ling. Suite des initiales de plusieurs mots qui forme un mot prononcé avec les noms des lettres. O.N.U. se prononce comme un sigle ou comme un acronyme. Dérivé formé sur un sigle (ex. cégétiste, de C.G.T.)

Grand dictionnaire terminologique


abréviation [linguistique]
Forme graphique abrégée d'un mot résultant du retranchement d'une partie des lettres de ce mot. [Office de la langue française, 2001]
acronyme [linguistique]
Sigle dont la prononciation est syllabique.
Note(s): OVNI est un acronyme, puisqu'il est prononcé comme un mot ordinaire. [Office de la langue française, 2001]
sigle [linguistique]
Groupe de lettres initiales de plusieurs mots dont la prononciation est syllabique, alphabétique ou les deux.
Note(s): Si la prononciation d'un sigle est syllabique, on le dénomme plus précisément acronyme. Par exemple, ADN est un sigle au sens strict et OVNI est un acronyme. [Office de la langue française, 2001]
sigle [sigle] (n.m.) terme normalisé par un organisme international
Dénomination abrégée constituée par la suite des initiales des mots ou de certains des mots et éventuellement par des chiffres qui composent la dénomination complète.
English: logogram.

Diccionario didáctico de español intermedio

abreviatura s.f.
1. Representación de una palabra en la escritura con sólo una o varias de sus letras: La abreviatura de 'doctor' es 'dr.' y la de kilogramo, 'kg'.
2. Palabra así reducida: En las primeras hojas del diccionario está la lista de abreviaturas utilizadas.
acrónimo s.m.
Palabra formada a partir de una sigla que se ha lexicalizado y que ha adquirido categoría gramatical: 'Sida' es el acrónimo de 'Síndrome de Inmunodeficiencia Adquirida'.
sigla s.f.
Palabra formada con las iniciales de otras palabras que forman un enunciado: 'ONU' es la sigla de 'Organización de las Naciones Unidas'.

Diccionarios de


1. f. LING. Representación abreviada de una palabra en la lengua escrita: "sra." es la abreviatura de "señora".
2. LING. Palabra resultante de esta reducción gráfica: lista de abreviaturas.
3. Compendio, resumen: presentó una abreviatura del trabajo.
4. en abreviatura loc. adv. Sin alguna de las letras que en la escritura corresponden a cada palabra.
m. LING. Palabra formada por las iniciales, y a veces por más letras, de otras palabras: "RENFE" es el acrónimo de Red Nacional de Ferrocarriles Españole.
1. f. Letra inicial, o conjunto de ellas, que se emplea como abreviatura: S.D.M. son las siglas de Su Divina Majestad.
2. Palabra o rótulo formado con estas iniciales, como ONU o CEE.


1. f. Acortamiento en la escritura de una o varias palabras, representadas con una o varias de sus letras: admón por administración; d.e.p. por descanse en paz.
2. Formación resultante de dicho acortamiento.
3. Abreviaduría.
4. Compendio o resumen.
5. fam., fest. Con brevedad o prisa. -
6. loc. adv. En ~, sin alguna de las letras que en la escritura corresponden a cada palabra.
m. Palabra compuesta por acronimia.
sigla (b. l., cifras, abreviaturas)
1. f. Letra inicial usada como abreviatura: S.A, siglas de Sociedad Anónima.
2. Rótulo o denominación que se forma con varias siglas.
3. Abreviatura formada por las letras iniciales de nombres propios.

Comments and Conclusions

The term “abbreviation” appears to have two meanings in this context, which most dictionaries conflate into one definition:

1. The shortened form of a word.
2. Shorthand for “abbreviated/shortened form”; superset of abbreviation (1), initialism and acronym.

Some abbreviations and acronyms are spelled and used as nouns, for example:

Abbreviated forms are sometimes lexicalized: they become words in their own right, so it becomes possible to base other words on them (adjectives, compounds, etc):

In some cases, the expanded form only exists in a foreign language, so it may be more helpful to provide an explanation in the host language instead of the original language, or to use an alternative from the host language:

In some cases, only the abbreviation has been borrowed and providng the expansion might cause confusion (a.m. and p.m.), but in other cases, the expanded form is also common (for example, “etcetera” and “versus” en English and Dutch). (A short list of Latin abbrevations is available on the website of the University of Liverpool.)

For some acronyms, the original meaning is offically dropped because it is no longer considered relevant, for example:

Some abbreviations acquire a connotation that is not present in the orginal form, for example:

Note that contractions (e.g. wanna, aren't, won't, …) are also shortened forms but that we probably don't want to include them in a criterion that requires expanded forms, or at least not in English.

Also, if you assume that “word” in any of the definitions quoted above implies “pronounceable” and that initialisms can't be pronounced as words, some languages may not have a word for “initialism”. I think this is the case for Dutch and German.

Previous Discussions on W3C Mailing Lists

Al Gilman, 2 February 1998: Re: ABBR and ACRONYM.

(And a number of other long threads.)

Christophe Strobbe: Christophe.Strobbe ( @ )