flying drainpipe vs ramjet engine

flying drainpipe and ramjet engine both are nouns.

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

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

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

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

flying drainpipe (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