emperor vs imperial

emperor and imperial both are nouns.

Word	Noun	Adjective	Verb	Adverb
emperor	Yes	No	No	No
imperial	Yes	Yes	No	No

emperor (noun)	imperial (noun)
large richly colored butterfly	a piece of luggage carried on top of a coach
large moth of temperate forests of Eurasia having heavily scaled transparent wings	a small tufted beard worn by Emperor Napoleon III
red table grape of California
the male ruler of an empire

emperor (adjective)	imperial (adjective)
	befitting or belonging to an emperor or empress
	relating to or associated with an empire
	of or belonging to the British Imperial System of weights and measures
	belonging to or befitting a supreme ruler