Noah Webster's Dictionary 1. (a.) Being at, or pertaining to, midday; belonging to, or passing through, the highest point attained by the sun in his diurnal course. 2. (a.) Pertaining to the highest point or culmination; as, meridian splendor. 3. (a.) Midday; noon. 4. (a.) Hence: The highest point, as of success, prosperity, or the like; culmination. 5. (n.) A great circle of the sphere passing through the poles of the heavens and the zenith of a given place. It is crossed by the sun at midday. 6. (n.) A great circle on the surface of the earth, passing through the poles and any given place; also, the half of such a circle included between the poles.

Multi-Version Concordance Meridian (1 Occurrence) Isaiah 38:10 I said, In the meridian of my days I shall go to the gates of Sheol: I am deprived of the rest of my years. (DBY)