hilltop vs summit

hilltop and summit both are nouns.

Word	Noun	Adjective	Verb	Adverb
hilltop	Yes	No	No	No
summit	Yes	No	Yes	No

As nouns, summit is a hypernym of hilltop; that is, summit is a word with a broader meaning than hilltop:

Other hypernyms of hilltop include crest, crown, peak, tip, top.

hilltop (noun)	summit (noun)
the peak of a hill	a meeting of heads of governments
	the top or extreme point of something (usually a mountain or hill)
	the highest level or degree attainable; the highest stage of development

hilltop (verb)	summit (verb)
	reach the summit (of a mountain)