pirouette vs twirl

pirouette and twirl both are nouns.

Word	Noun	Adjective	Verb	Adverb
pirouette	Yes	No	Yes	No
twirl	Yes	No	Yes	No

As nouns, twirl is a hypernym of pirouette; that is, twirl is a word with a broader meaning than pirouette:

pirouette: (ballet) a rapid spin of the body (especially on the toes as in ballet)
twirl: the act of rotating rapidly

Other hypernyms of pirouette include spin, twist, twisting, whirl.

pirouette (noun)	twirl (noun)
(ballet) a rapid spin of the body (especially on the toes as in ballet)	the act of rotating rapidly
	a sharp bend in a line produced when a line having a loop is pulled tight

pirouette (verb)	twirl (verb)
do a pirouette, usually as part of a dance	turn in a twisting or spinning motion
	cause to spin