double reed vs cromorne

double reed and cromorne both are nouns.

Word	Noun	Adjective	Verb	Adverb
double reed	Yes	No	No	No
cromorne	Yes	No	No	No

As nouns, cromorne is a hyponym of double reed; that is, cromorne is a word with a more specific, narrower meaning than double reed:

double reed: a woodwind that has a pair of joined reeds that vibrate together
cromorne: a Renaissance woodwind with a double reed and a curving tube (crooked horn)

Other hyponyms of double reed include bassoon, cor anglais, English horn, crumhorn, krummhorn, hautbois, hautboy, oboe.

double reed (noun)	cromorne (noun)
a pair of joined reeds that vibrate together to produce the sound in some woodwinds	a Renaissance woodwind with a double reed and a curving tube (crooked horn)
a woodwind that has a pair of joined reeds that vibrate together