raincoat vs trench coat

raincoat and trench coat both are nouns.

Word	Noun	Adjective	Verb	Adverb
raincoat	Yes	No	No	No
trench coat	Yes	No	No	No

As nouns, trench coat is a hyponym of raincoat; that is, trench coat is a word with a more specific, narrower meaning than raincoat:

Other hyponyms of raincoat include Burberry, mac, macintosh, mack, mackintosh.

raincoat (noun)	trench coat (noun)
a water-resistant coat	a military style raincoat; belted with deep pockets