heater vs hummer

heater and hummer both are nouns.

Word	Noun	Adjective	Verb	Adverb
heater	Yes	No	No	No
hummer	Yes	No	No	No

As nouns, heater and hummer are synonyms defined as:

Other synonyms of heater include bullet, fastball, smoke.

heater (noun)	hummer (noun)
(baseball) a pitch thrown with maximum velocity	(baseball) a pitch thrown with maximum velocity
device that heats water or supplies warmth to a room	a singer who produces a tune without opening the lips or forming words