tremble vs shudder

tremble and shudder both are nouns.

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

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

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

tremble (noun)	shudder (noun)
a reflex motion caused by cold or fear or excitement	an involuntary vibration (as if from illness or fear)
	an almost pleasurable sensation of fright

tremble (verb)	shudder (verb)
move or jerk quickly and involuntarily up and down or sideways	shake, as from cold
	tremble convulsively, as from fear or excitement