explain vs comment

explain is not a noun while comment is a noun.

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

As verbs, comment is a hyponym of explain; that is, comment is a word with a more specific, narrower meaning than explain:

Other hyponyms of explain include interpret, rede, account for, naturalize, clarify, clear up, elucidate.

explain (noun)	comment (noun)
	a statement that expresses a personal opinion or belief or adds information
	a written explanation or criticism or illustration that is added to a book or other textual material
	a report (often malicious) about the behavior of other people

explain (verb)	comment (verb)
make plain and comprehensible	make or write a comment on
define	provide interlinear explanations for words or phrases
serve as a reason or cause or justification of	explain or interpret something