shakiness vs tremor

shakiness and tremor both are nouns.

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

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

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

Other hyponyms of shakiness include tremolo.

shakiness (noun)	tremor (noun)
the quality of being unstable and insecure	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)

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