containment vs contain

containment is a noun but contain is not a noun.

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

containment (noun)	contain (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

containment (verb)	contain (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