Mars \Mars\ (m[aum]rz), prop. n. [L. Mars, gen. Martis, archaic Mavors, gen. Mavortis.] 1. (Rom. Myth.) The god of war and husbandry. [1913 Webster] 2. (Astron.) One of the planets of the solar system, the fourth in order from the sun, or the next beyond the earth, having a diameter of about 4,200 miles, a period of 687 days, and a mean distance of 141,000,000 miles. It is conspicuous for the redness of its light. [1913 Webster] 3. (Alchemy) The metallic element iron, the symbol of which [male] was the same as that of the planet Mars. [Archaic] --Chaucer. [1913 Webster] {Mars brown}, a bright, somewhat yellowish, brown. [1913 Webster]