a shortened or contracted form of a word or phrase, used to represent the whole, as Dr. for Doctor, U.S. for United States, lb. for pound.

an act of abbreviating; state or result of being abbreviated; reduction in length, duration, etc.; abridgment.

noun

augmentation , enlargement , expansion , extension , increase

noun

abridgement , abstract , abstraction , clipping , compendium , compression , condensation , contraction , digest , outline , precis , reduction , sketch , summary , syllabus , synopsis