quirk vs crotchet

quirk and crotchet both are nouns.

Word	Noun	Adjective	Verb	Adverb
quirk	Yes	No	Yes	No
crotchet	Yes	No	No	No

As nouns, quirk and crotchet are synonyms defined as:

Other synonyms of quirk include oddity, queerness, quirkiness.

quirk (noun)	crotchet (noun)
a narrow groove beside a beading	a small tool or hooklike implement
a strange attitude or habit	a strange attitude or habit
	a musical note having the time value of a quarter of a whole note
	a sharp curve or crook; a shape resembling a hook

quirk (verb)	crotchet (verb)
twist or curve abruptly