"seaman, sailor, one who directs or assists in navigating a ship," mid-13c., from Anglo-French mariner, Old French marinier "seaman, sailor" (12c.), from Medieval Latin marinarius "sailor," "of the sea, maritime," from Latin marinus "of the sea," from mare "sea, the sea, seawater," from PIE root *mori- "body of water." Earlier and long more common than sailor. A sailor also could be a brimgeist in Old English.