meridian (n.) Look up meridian at
mid-14c., "noon," from Old French meridien "of the noon time, midday; the Meridian; southerner" (12c.), and directly from Latin meridianus "of midday, of noon, southerly, to the south," from meridies "noon, south," from meridie "at noon," altered by dissimilation from pre-Latin *medi die, locative of medius "mid-" (see medial (adj.)) + dies "day" (see diurnal). Cartographic sense first recorded late 14c. Figurative uses tend to suggest "point of highest development or fullest power."

The city in Mississippi, U.S., was settled 1854 (as Sowashee Station) at a railway junction and given its current name in 1860, supposedly by people who thought meridian meant "junction" (they perhaps confused the word with median).