contraction vs shrinkage

contraction and shrinkage both are nouns.

Word	Noun	Adjective	Verb	Adverb
contraction	Yes	No	No	No
shrinkage	Yes	No	No	No

As nouns, shrinkage is a hypernym of contraction; that is, shrinkage is a word with a broader meaning than contraction:

Other hypernyms of contraction include shrinking.

contraction (noun)	shrinkage (noun)
the act of decreasing (something) in size or volume or quantity or scope	the act of stealing goods that are on display in a store
(physiology) a shortening or tensing of a part or organ (especially of a muscle or muscle fiber)	the amount by which something shrinks
a word formed from two or more words by omitting or combining some sounds	process or result of becoming less or smaller
the process or result of becoming smaller or pressed together