vertex vs peak

vertex and peak both are nouns.

Word	Noun	Adjective	Verb	Adverb
vertex	Yes	No	No	No
peak	Yes	No	Yes	No

As nouns, vertex and peak are synonyms defined as:

Other synonyms of vertex include acme, apex.

vertex (noun)	peak (noun)
the point of intersection of lines or the point opposite the base of a figure	a brim that projects to the front to shade the eyes
the highest point (of something)	the top or extreme point of something (usually a mountain or hill)
	the highest point (of something)
	the most extreme possible amount or value
	a V shape
	the highest level or degree attainable; the highest stage of development
	the period of greatest prosperity or productivity

vertex (verb)	peak (verb)
	to reach the highest point; attain maximum intensity, activity