Sinus Meridianii: Meaning and Definition of

Si•nus Me•rid•i•a•ni•i

Pronunciation: (sē'nus mu-rid"ē-ä'nē-ē", sī'nus mu-rid"ē-ā'nē-ī"), [key]
  1. an area on the equator of Mars, appearing as a dark region when viewed telescopically from the earth.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.