What is the meaning of Meridian?

noun

• The highest level or degree attainable; the highest stage of development.
  • usage: "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"
  • synonyms: acme, height, elevation, peak, pinnacle, summit, superlative, tiptop, top
• 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.
  • usage: "all points on the same meridian have the same longitude"
  • synonyms: line of longitude

adjective

• Of or happening at noon.
  • usage: "meridian hour"
• Being at the best stage of development."our manhood's prime vigor- Robert Browning
  • synonyms: prime