top vs pinnacle

top and pinnacle both are nouns.

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

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

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

As nouns, top and pinnacle are synonyms defined as:

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

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

top (noun)	pinnacle (noun)
a garment (especially for women) that extends from the shoulders to the waist or hips	(architecture) a slender upright spire at the top of a buttress or tower
covering for a hole (especially a hole in the top of a container)	a lofty peak
a canvas tent to house the audience at a circus performance	the highest level or degree attainable; the highest stage of development
a conical child's plaything tapering to a steel point on which it can be made to spin
platform surrounding the head of a lower mast
the greatest possible intensity
the highest or uppermost side of anything
the upper part of anything
the top or extreme point of something (usually a mountain or hill)
the highest level or degree attainable; the highest stage of development
the first half of an inning; while the visiting team is at bat

top (adjective)	pinnacle (adjective)
situated at the top or highest position

top (verb)	pinnacle (verb)
be the culminating event	raise on or as if on a pinnacle
finish up or conclude	surmount with a pinnacle
cut the top off
strike (the top part of a ball in golf, baseball, or pool) giving it a forward spin
pass by, over, or under without making contact
reach or ascend the top of
provide with a top or finish the top (of a structure)
be superior or better than some standard
be at the top of or constitute the top or highest point
be ahead of others; be the first