late 14c., marcien "of, pertaining to, or characteristic of the planet Mars" (originally in reference to astrological influence), from Latin Martius "sacred to (the god) Mars; pertaining to (the planet) Mars," from Mars (genitive Martis; see Mars). From mid-15c. as "of or pertaining to the god Mars, warlike;" also sometimes "of or pertaining to the month of March" (1620s). The noun meaning "an inhabitant of the planet Mars" is attested by 1877.
updated on November 28, 2018