meridian - noun

the highest level or degree attainable; the highest stage of development

a town in eastern Mississippi

an imaginary great circle on the surface of the earth passing through the north and south poles at right angles to the equator

meridian - adjective

• of or happening at noon
• being at the best stage of development

meridian - thesaurus

acme   elevation   height   peak   pinnacle   prime   summit   superlative   tiptop   top