jet plane vs turbojet

jet plane and turbojet both are nouns.

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

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

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

jet plane (noun)	turbojet (noun)
an airplane powered by one or more jet engines	a jet engine in which a fan driven by a turbine provides extra air to the burner and gives extra thrust
	an airplane propelled by a fanjet engine