meridian

Adjective

• being at the best stage of development
  • our manhood's prime vigor- Robert Browning
    

• of or happening at noon
  • meridian hour
    

Noun

• an imaginary great circle on the surface of the earth passing through the north and south poles at right angles to the equator
  • all points on the same meridian have the same longitude
    

• a town in eastern Mississippi

• the highest level or degree attainable; the highest stage of development
  • his landscapes were deemed the acme of beauty
    
  • the artist's gifts are at their acme
    
  • at the height of her career
    
  • the peak of perfection
    
  • summer was at its peak
    
  • ...catapulted Einstein to the pinnacle of fame
    
  • the summit of his ambition
    
  • so many highest superlatives achieved by man
    
  • at the top of his profession
    

Related words

• Synonyms: 
  prime , line of longitude , Meridian