fanjet engine vs jet engine

fanjet engine and jet engine both are nouns.

Word	Noun	Adjective	Verb	Adverb
fanjet engine	Yes	No	No	No
jet engine	Yes	No	No	No

As nouns, jet engine is a hypernym of fanjet engine; that is, jet engine is a word with a broader meaning than fanjet engine:

fanjet engine: a jet engine in which a fan driven by a turbine provides extra air to the burner and gives extra thrust
jet engine: a gas turbine produces a stream of hot gas that propels a jet plane by reaction propulsion

fanjet engine (noun)	jet engine (noun)
a jet engine in which a fan driven by a turbine provides extra air to the burner and gives extra thrust	a gas turbine produces a stream of hot gas that propels a jet plane by reaction propulsion