expansion vs expand

expansion is a noun but expand is not a noun.

Word	Noun	Adjective	Verb	Adverb
expansion	Yes	No	No	No
expand	No	No	Yes	No

expansion (noun)	expand (noun)
the act of increasing (something) in size or volume or quantity or scope
adding information or detail
a discussion that provides additional information
a function expressed as a sum or product of terms

expansion (verb)	expand (verb)
	grow vigorously
	exaggerate or make bigger
	become larger in size or volume or quantity
	expand the influence of
	make bigger or wider in size, volume, or quantity
	add details, as to an account or idea; clarify the meaning of and discourse in a learned way, usually in writing
	extend in one or more directions