ramjet vs ramjet engine

ramjet and ramjet engine both are nouns.

Word	Noun	Adjective	Verb	Adverb
ramjet	Yes	No	No	No
ramjet engine	Yes	No	No	No

As nouns, ramjet and ramjet engine are synonyms defined as:

ramjet and ramjet engine: a simple type of jet engine; must be launched at high speed

Other synonyms of ramjet include atherodyde, athodyd, flying drainpipe.

ramjet (noun)	ramjet engine (noun)
a simple type of jet engine; must be launched at high speed	a simple type of jet engine; must be launched at high speed