explain vs explanation

explain is not a noun while explanation is a noun.

Word	Noun	Adjective	Verb	Adverb
explain	No	No	Yes	No
explanation	Yes	No	No	No

explain (noun)	explanation (noun)
	thought that makes something comprehensible
	a statement that makes something comprehensible by describing the relevant structure or operation or circumstances etc.
	the act of explaining; making something plain or intelligible

explain (verb)	explanation (verb)
make plain and comprehensible
define
serve as a reason or cause or justification of