clay pipe vs pipe

clay pipe and pipe both are nouns.

Word	Noun	Adjective	Verb	Adverb
clay pipe	Yes	No	No	No
pipe	Yes	No	Yes	No

As nouns, pipe is a hypernym of clay pipe; that is, pipe is a word with a broader meaning than clay pipe:

Other hypernyms of clay pipe include tobacco pipe.

clay pipe (noun)	pipe (noun)
a pipe made of clay	a long tube made of metal or plastic that is used to carry water or oil or gas etc.
	a tube with a small bowl at one end; used for smoking tobacco
	the flues and stops on a pipe organ
	a tubular wind instrument
	a hollow cylindrical shape