etymologist vs lexicologist

etymologist and lexicologist both are nouns.

Word	Noun	Adjective	Verb	Adverb
etymologist	Yes	No	No	No
lexicologist	Yes	No	No	No

As nouns, lexicologist is a hypernym of etymologist; that is, lexicologist is a word with a broader meaning than etymologist:

etymologist: a lexicographer who specializes in etymology
lexicologist: a compiler or writer of a dictionary; a student of the lexical component of language

Other hypernyms of etymologist include lexicographer.

etymologist (noun)	lexicologist (noun)
a lexicographer who specializes in etymology	a compiler or writer of a dictionary; a student of the lexical component of language