Source : Webster's Revised Unabridged Dictionary (1913)

Roustabout \Roust"a*bout`\, n. [Etymol. uncertain.]
   A laborer, especially a deck hand, on a river steamboat, who
   moves the cargo, loads and unloads wood, and the like; in an
   opprobrious sense, a shiftless vagrant who lives by chance
   jobs. [Western U.S.]

Source : WordNet®

roustabout
     n : a member of a ship's crew who performs manual labor [syn: {deckhand}]