notion vs hunch

notion and hunch both are nouns.

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

As nouns, hunch is a hyponym of notion; that is, hunch is a word with a more specific, narrower meaning than notion:

Other hyponyms of notion include presence, effect, first blush, intuition, suspicion.

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

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