contraction

noun

1. 1

   the act of decreasing (something) in size or volume or quantity or scope

2. 2

   (physiology) a shortening or tensing of a part or organ (especially of a muscle or muscle fiber)

3. 3

   a 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'

4. 4

   the process or result of becoming smaller or pressed together

   the contraction of a gas on cooling