hint vs clue in

hint is a noun but clue in is not a noun.

Word	Noun	Adjective	Verb	Adverb
hint	Yes	No	Yes	No
clue in	No	No	Yes	No

As verbs, clue in is a hyponym of hint; that is, clue in is a word with a more specific, narrower meaning than hint:

Other hyponyms of hint include adumbrate, insinuate, intimate, advert, allude, touch.

hint (noun)	clue in (noun)
an indirect suggestion
a slight indication
an indication of potential opportunity
a slight but appreciable amount
a just detectable amount

hint (verb)	clue in (verb)
drop a hint; intimate by a hint	provide someone with a clue