tremble vs throb

tremble and throb both are nouns.

Word	Noun	Adjective	Verb	Adverb
tremble	Yes	No	Yes	No
throb	Yes	No	Yes	No

As verbs, throb is a hyponym of tremble; that is, throb is a word with a more specific, narrower meaning than tremble:

Other hyponyms of tremble include shiver, shudder, thrill, palpitate, quake, quiver.

tremble (noun)	throb (noun)
a reflex motion caused by cold or fear or excitement	an instance of rapid strong pulsation (of the heart)
	a deep pulsating type of pain

tremble (verb)	throb (verb)
move or jerk quickly and involuntarily up and down or sideways	tremble convulsively, as from fear or excitement
	expand and contract rhythmically; beat rhythmically
	pulsate or pound with abnormal force