twitch vs fasciculation

twitch and fasciculation both are nouns.

Word	Noun	Adjective	Verb	Adverb
twitch	Yes	No	Yes	No
fasciculation	Yes	No	No	No

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

Other hyponyms of twitch include tic, blepharism, fibrillation.

twitch (noun)	fasciculation (noun)
a sudden muscle spasm; especially one caused by a nervous condition	muscular twitching of contiguous groups of muscle fibers

twitch (verb)	fasciculation (verb)
make an uncontrolled, short, jerky motion
squeeze tightly between the fingers
move or pull with a sudden motion
toss with a sharp movement so as to cause to turn over in the air
move with abrupt, seemingly uncontrolled motions