contain vs containment

contain is not a noun while containment is a noun.

Word	Noun	Adjective	Verb	Adverb
contain	No	No	Yes	No
containment	Yes	No	No	No

contain (noun)	containment (noun)
	the act of containing; keeping something from spreading
	(physics) a system designed to prevent the accidental release of radioactive material from a reactor
	a policy of creating strategic alliances in order to check the expansion of a hostile power or ideology or to force it to negotiate peacefully

contain (verb)	containment (verb)
hold back, as of a danger or an enemy; check the expansion or influence of
lessen the intensity of; temper; hold in restraint; hold or keep within limits
include or contain; have as a component
be divisible by
contain or hold; have within
be capable of holding or containing