abbreviation

Short definition from Wiktionary

Noun

1. 1
   The result of shortening or reducing; abridgment.
2. 2
   A shortened or contracted form of a word or phrase used to represent the whole, using omission of letters, and sometimes substitution of letters, or duplication of initial letters to signify plurality, including signs such as +, =, @.
3. 3
   The process of abbreviating.
4. 4
   A notation used in music score to denote a direction, as pp or mf.
5. 5
   One or more dashes through the stem of a note, dividing it respectively into quavers, semiquavers, demisemiquavers, or hemidemisemiquavers.
6. 6
   Any convenient short form used as a substitution for an understood or inferred whole.
7. 7
   Loss during evolution of the final stages of the ancestral ontogenetic pattern.
8. 8
   Reduction to lower terms, as a fraction.