snowbird

noun

1. A bird, Junco hyemalis, the dark-eyed junco.
2. A migratory bird seen primarily in the winter time.
3. The snow bunting (Plectrophenax nivalis).
4. A person, usually one who is retired, who travels from a cold climate to a warmer one in the winter; one who overwinters elsewhere.
5. (US, slang)One who enlists in fall to desert after winter.
6. (slang)Someone who uses cocaine illicitly.