shaking vs tremor

shaking and tremor both are nouns.

Word	Noun	Adjective	Verb	Adverb
shaking	Yes	No	No	No
tremor	Yes	No	Yes	No

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

shaking: a shaky motion
tremor: shaking or trembling (usually resulting from weakness or stress or disease)

Other hyponyms of shaking include tremolo.

shaking (noun)	tremor (noun)
the act of causing something to move up and down (or back and forth) with quick movements	an involuntary vibration (as if from illness or fear)
a shaky motion	a small earthquake
	shaking or trembling (usually resulting from weakness or stress or disease)

shaking (verb)	tremor (verb)
	shake with seismic vibrations