abbreviation

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. The act or product of shortening.
2. n. A shortened form of word or phrase used chiefly in writing to represent the complete form, such as Mass. for Massachusetts or USMC for United States Marine Corps.

Century Dictionary and Cyclopedia

1. n. The act of abbreviating, shortening, or contracting; the state of being abbreviated; abridgment.
2. n. A shortened or contracted form; a part used for the whole. Specifically, a part of a word, phrase, or title so used; a syllable, generally the initial syllable, used for the whole word; a letter, or a series of letters, standing for a word or words: as, Esq. for esquire; A. D. for Anno Domini; F. R. S. for Fellow of the Royal Society.
3. n. In mathematics, a reduction of fractions to the lowest terms.
4. n. In music, a method of notation by means of which certain repeated notes, chords, or passages are indicated without being written out in full. There are various forms of abbreviation, the most common of which are here shown: Synonyms Abbreviation, Contraction. An abbreviation of a word is strictly a part of it, generally the first letter or syllable, taken for the whole, with no indication of the remaining portion: as, A. D. for Anno Domini; Gen. for Genesis; mathematics for mathematics; Alex. for Alexander. A contraction, on the other hand, is made by the elision of certain letters or syllables from the body of the word, but in such a manner as to indicate the whole word: as, recd. payt. or rec'd pay't for received payment; contd. for contracted or continued; Wm. for William. In common usage, however, this distinction is not always observed.
5. n. . Other marks of abbreviation are: One indicating that a rest is to extend for several measures, and consisting either of a general character in the staff with a figure above, or simply of a figure in the staff denoting the intended number of measures, thus

Wiktionary

1. n. music A notation used in music score to denote a direction, as pp or mf.
2. n. music One or more dashes through the stem of a note, dividing it respectively into quavers, semiquavers, demisemiquavers, or hemidemisemiquavers.
3. n. Any convenient short form used as a substitutuion for an understood or inferred whole.
4. n. biology Loss during evolution of the final stages of the ancestral ontogenetic pattern.
5. n. mathematics Reduction to lower terms, as a fraction.

GNU Webster's 1913

1. n. The act of shortening, or reducing.
2. n. The result of abbreviating; an abridgment.
3. n. The form to which a word or phrase is reduced by contraction and omission; a letter or letters, standing for a word or phrase of which they are a part; as, Gen. for Genesis; U.S.A. for United States of America.
4. n. (Mus.) One dash, or more, through the stem of a note, dividing it respectively into quavers, semiquavers, or demi-semiquavers.

WordNet 3.0

1. n. a shortened form of word or phrase
2. n. shortening something by omitting parts of it