roof peak vs apex

roof peak and apex both are nouns.

Word	Noun	Adjective	Verb	Adverb
roof peak	Yes	No	No	No
apex	Yes	No	No	No

As nouns, apex is a hypernym of roof peak; that is, apex is a word with a broader meaning than roof peak:

Other hypernyms of roof peak include acme, peak, vertex.

roof peak (noun)	apex (noun)
the highest point of a roof	the highest point (of something)
	the point on the celestial sphere toward which the sun and solar system appear to be moving relative to the fixed stars