vroom vs roar

vroom and roar both are nouns.

Word	Noun	Adjective	Verb	Adverb
vroom	Yes	No	Yes	No
roar	Yes	No	Yes	No

As verbs, roar is a hypernym of vroom; that is, roar is a word with a broader meaning than vroom:

Other hypernyms of vroom include howl.

vroom (noun)	roar (noun)
the roaring sound made by a motor that is running at high speed	a very loud utterance (like the sound of an animal)
	a deep prolonged loud noise
	the sound made by a lion

vroom (verb)	roar (verb)
make a loud, roaring sound, as of a car engine, while moving	laugh unrestrainedly and heartily
	make a loud noise, as of wind, water, or vehicles
	emit long loud cries
	utter words loudly and forcefully
	make a loud noise, as of animal
	act or proceed in a riotous, turbulent, or disorderly way