Topsail
Pronunciation : Top"sail`
Part of Speech : n.
Definition : Defn: In a square-rigged vessel, the sail next above the lowermost sail on a mast. This sail is the one most frequently reefed or furled in working the ship. In a fore-and-aft rigged vessel, the sail set upon and above the gaff. See Cutter, Schooner, Sail, and Ship. Topsail schooner. (Naut.) See Schooner, and Illustration in Appendix.
(Naut.)
Source : Webster's Unabridged Dictionary, 1913