fold vs twirl

fold and twirl both are nouns.

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

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

fold: an angular or rounded shape made by folding
twirl: a sharp bend in a line produced when a line having a loop is pulled tight

Other hyponyms of fold include plait, pleat, kink, twist, pucker, ruck, accordion fold, concertina fold, z-fold, zig-zag fold.

fold (noun)	twirl (noun)
the act of folding	the act of rotating rapidly
a pen for sheep	a sharp bend in a line produced when a line having a loop is pulled tight
a folded part (as in skin or muscle)
a group of people who adhere to a common faith and habitually attend a given church
a group of sheep or goats
a geological process that causes a bend in a stratum of rock
an angular or rounded shape made by folding

fold (verb)	twirl (verb)
incorporate a food ingredient into a mixture by repeatedly turning it over without stirring or beating	turn in a twisting or spinning motion
become folded or folded up	cause to spin
bend or lay so that one part covers the other
confine in a fold, like sheep
cease to operate or cause to cease operating