1.(physiology) a shortening or tensing of a part or organ (especially of a muscle or muscle fiber)
2.the process or result of becoming smaller or pressed together;
the contraction of a gas on cooling
3.a word formed from two or more words by omitting or combining some sounds;
`won't' is a contraction of `will not'
4.the act of decreasing (something) in size or volume or quantity or scope