hunch vs notion

hunch and notion both are nouns.

Word	Noun	Adjective	Verb	Adverb
hunch	Yes	No	Yes	No
notion	Yes	No	No	No

As nouns, notion is a hypernym of hunch; that is, notion is a word with a broader meaning than hunch:

Other hypernyms of hunch include belief, feeling, impression, opinion.

hunch (noun)	notion (noun)
the act of bending yourself into a humped position	(usually plural) small personal articles or clothing or sewing items
an impression that something might be the case	a general inclusive concept
	an odd or fanciful or capricious idea
	a vague idea in which some confidence is placed

hunch (verb)	notion (verb)
round one's back by bending forward and drawing the shoulders forward