Webster's Revised Unabridged Dictionary · 1913

Martian

Martian , proper adjective

[Latin Martius.]

Of or pertaining to Mars, the Roman god of war, or to the planet bearing his name; martial.

Martian , proper noun

An inhabitant of the planet Mars; -- fictional or hypothetical. — Du Maurier

In science fiction, it has often been postulated that there are intelligent creatures living on Mars, but no strong evidence of any form of life on Mars has been observed up to the end of 1998.