summit vs pinnacle

summit and pinnacle both are nouns.

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

As nouns, pinnacle is a hyponym of summit; that is, pinnacle is a word with a more specific, narrower meaning than summit:

Other hyponyms of summit include brow, hilltop, mountain peak.

As nouns, summit and pinnacle are synonyms defined as:

summit and pinnacle: the highest level or degree attainable; the highest stage of development

Other synonyms of summit include acme, elevation, height, meridian, peak, superlative, tiptop, top.

summit (noun)	pinnacle (noun)
a meeting of heads of governments	(architecture) a slender upright spire at the top of a buttress or tower
the top or extreme point of something (usually a mountain or hill)	a lofty peak
the highest level or degree attainable; the highest stage of development	the highest level or degree attainable; the highest stage of development

summit (verb)	pinnacle (verb)
reach the summit (of a mountain)	raise on or as if on a pinnacle
	surmount with a pinnacle