pipe vs yowl

pipe and yowl both are nouns.

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

As verbs, yowl is a hyponym of pipe; that is, yowl is a word with a more specific, narrower meaning than pipe:

Other hyponyms of pipe include caterwaul.

pipe (noun)	yowl (noun)
a long tube made of metal or plastic that is used to carry water or oil or gas etc.	a very loud utterance (like the sound of an animal)
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