propjet vs propeller plane

propjet and propeller plane both are nouns.

Word	Noun	Adjective	Verb	Adverb
propjet	Yes	No	No	No
propeller plane	Yes	No	No	No

As nouns, propeller plane is a hypernym of propjet; that is, propeller plane is a word with a broader meaning than propjet:

propjet: an airplane with an external propeller that is driven by a turbojet engine
propeller plane: an airplane that is driven by a propeller

propjet (noun)	propeller plane (noun)
an airplane with an external propeller that is driven by a turbojet engine	an airplane that is driven by a propeller