earthquake vs flutter

earthquake and flutter both are nouns.

Word	Noun	Adjective	Verb	Adverb
earthquake	Yes	No	No	No
flutter	Yes	No	Yes	No

As nouns, flutter is a hypernym of earthquake; that is, flutter is a word with a broader meaning than earthquake:

Other hypernyms of earthquake include commotion, disruption, disturbance, hoo-ha, hoo-hah, hurly burly, kerfuffle, to-do.

earthquake (noun)	flutter (noun)
shaking and vibration at the surface of the earth resulting from underground movement along a fault plane or from volcanic activity	the act of moving back and forth
a disturbance that is extremely disruptive	the motion made by flapping up and down
	abnormally rapid beating of the auricles of the heart (especially in a regular rhythm); can result in heart block
	a disorderly outburst or tumult

earthquake (verb)	flutter (verb)
	wink briefly
	beat rapidly
	move back and forth very rapidly
	move along rapidly and lightly; skim or dart
	flap the wings rapidly or fly with flapping movements