rocket propellant vs propellent

rocket propellant and propellent both are nouns.

Word	Noun	Adjective	Verb	Adverb
rocket propellant	Yes	No	No	No
propellent	Yes	Yes	No	No

As nouns, propellent is a hypernym of rocket propellant; that is, propellent is a word with a broader meaning than rocket propellant:

Other hypernyms of rocket propellant include burster, bursting charge, charge, explosive charge, propellant.

rocket propellant (noun)	propellent (noun)
an explosive charge that propels a rocket	any substance that propels

rocket propellant (adjective)	propellent (adjective)
	tending to or capable of propelling