jet plane vs jumbo jet

jet plane and jumbo jet both are nouns.

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

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

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

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