jet plane vs jumbojet

jet plane and jumbojet both are nouns.

Word	Noun	Adjective	Verb	Adverb
jet plane	Yes	No	No	No
jumbojet	Yes	No	No	No

As nouns, jumbojet is a hyponym of jet plane; that is, jumbojet is a word with a more specific, narrower meaning than jet plane:

Other hyponyms of jet plane include fan-jet, fanjet, turbofan, turbojet, jetliner, jumbo jet, twinjet.

jet plane (noun)	jumbojet (noun)
an airplane powered by one or more jet engines	a very large jet plane