fore·cas·tle 
(fōksəl, fôrkăs′əl) also fo'c's'le (fōksəl)
(fōksəl, fôrkăs′əl) also fo'c's'le (fōksəl)n.
1. The section of the upper deck of a ship located at the bow forward of the foremast.
2. A superstructure at the bow of a merchant ship where the crew is housed. See Usage Note at boatswain.
[Middle English forecastel : fore-, fore- + castel, fortification; see CASTLE.]