decline vs contract out

decline is a noun but contract out is not a noun.

Word	Noun	Adjective	Verb	Adverb
decline	Yes	No	Yes	No
contract out	No	No	Yes	No

As verbs, contract out is a hyponym of decline; that is, contract out is a word with a more specific, narrower meaning than decline:

Other hyponyms of decline include disdain, freeze off, pooh-pooh, reject, scorn, spurn, turn down, regret, repudiate, disobey.

decline (noun)	contract out (noun)
a downward slope or bend
a gradual decrease; as of stored charge or current
change toward something smaller or lower
a condition inferior to an earlier condition; a gradual falling off from a better state; decline

decline (verb)	contract out (verb)
grow smaller	refuse to pay a levy to a union for political use
grow worse	assign a job to someone outside one's own business
show unwillingness towards
inflect for number, gender, case, etc.
go down
fall in value
not accept as true