acme vs apex

acme and apex both are nouns.

Word	Noun	Adjective	Verb	Adverb
acme	Yes	No	No	No
apex	Yes	No	No	No

As nouns, acme and apex are synonyms defined as:

Other synonyms of acme include peak, vertex.

acme (noun)	apex (noun)
the highest point (of something)	the highest point (of something)
the highest level or degree attainable; the highest stage of development	the point on the celestial sphere toward which the sun and solar system appear to be moving relative to the fixed stars