organ pipe vs reed pipe

organ pipe and reed pipe both are nouns.

Word	Noun	Adjective	Verb	Adverb
organ pipe	Yes	No	No	No
reed pipe	Yes	No	No	No

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

Other hyponyms of organ pipe include flue, flue pipe, labial pipe, organ stop.

organ pipe (noun)	reed pipe (noun)
the flues and stops on a pipe organ	organ pipe with a vibrating reed