shrill vs pipe up

shrill is an adjective but pipe up is not an adjective.

Word	Noun	Adjective	Verb	Adverb
shrill	No	Yes	Yes	No
pipe up	No	No	Yes	No

As verbs, shrill and pipe up are synonyms defined as:

Other synonyms of shrill include pipe, shriek.

shrill (adjective)	pipe up (adjective)
of colors that are bright and gaudy
having or emitting a high-pitched and sharp tone or tones
being sharply insistent on being heard

shrill (verb)	pipe up (verb)
utter a shrill cry	begin to play or sing
	utter a shrill cry