means A person who works aboard or navigates a ship, especially as a member of its crew.

from From Middle English 'sailer,' a doer-word built on 'sail' — itself from Old English 'segl,' shared with German 'Segel' and other Germanic tongues for the cloth that catches wind. The spelling drifted to 'sailor' over time, perhaps nudged by the agent-ending '-or' seen in Latin-flavored words like 'tailor' and 'governor.' At root, then, a sailor is simply 'one who sails' — one who lives by the sail.