khat vs stimulant

khat and stimulant both are nouns.

Word	Noun	Adjective	Verb	Adverb
khat	Yes	No	No	No
stimulant	Yes	Yes	No	No

As nouns, stimulant is a hypernym of khat; that is, stimulant is a word with a broader meaning than khat:

khat: the leaves of the shrub Catha edulis which are chewed like tobacco or used to make tea; has the effect of a euphoric stimulant
stimulant: a drug that temporarily quickens some vital process

Other hypernyms of khat include excitant, stimulant drug.

khat (noun)	stimulant (noun)
the leaves of the shrub Catha edulis which are chewed like tobacco or used to make tea; has the effect of a euphoric stimulant	a drug that temporarily quickens some vital process
	any stimulating information or event; acts to arouse action

khat (adjective)	stimulant (adjective)
	that stimulates