meridian vs acme

meridian and acme both are nouns.

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

As nouns, meridian and acme are synonyms defined as:

meridian and acme: the highest level or degree attainable; the highest stage of development

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

meridian (noun)	acme (noun)
an imaginary great circle on the surface of the earth passing through the north and south poles at right angles to the equator	the highest point (of something)
the highest level or degree attainable; the highest stage of development	the highest level or degree attainable; the highest stage of development

meridian (adjective)	acme (adjective)
of or happening at noon
being at the best stage of development