to shorten (a word or phrase) by omitting letters, substituting shorter forms, etc., so that the shortened form can represent the whole word or phrase, as ft. for foot, ab. for about, R.I. for Rhode Island, NW for Northwest, or Xn for Christian.
2.
to reduce (anything) in length, duration, etc.; make briefer: to abbreviate a speech.
Origin: 1400–50; late Middle English abbreviaten < Late Latin abbreviātus shortened (past participle of abbreviāre), equivalent to Latin ad-ad- + breviātus (brevi(s) short + -ātus-ate1)
mid-15c., from L. abbreviatus, pp. of abbreviare "to shorten" (see abbreviation). Also sometimes 15c. abbrevy, from M.Fr. abrevier (14c.), from L. abbreviare. Related: Abbreviated; abbreviating.