Open English Wordnet
Nouns
(n)contraction, muscular contraction, muscle contraction(physiology) a shortening or tensing of a part or organ (especially of a muscle or muscle fiber)
(n)compression, condensation, contractionthe process or result of becoming smaller or pressed together“the contraction of a gas on cooling”
(n)contractiona word formed from two or more words by omitting or combining some sounds“`won't' is a contraction of `will not'”, “`o'clock' is a contraction of `of the clock'”