'Topsail' definitions:
Definition of 'topsail'
From: WordNet
noun
A sail (or either of a pair of sails) immediately above the lowermost sail of a mast and supported by a topmast
Definition of 'Topsail'
From: GCIDE
- Topsail \Top"sail`\, n. (Naut.) 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. [1913 Webster]
- Topsail schooner. (Naut.) See Schooner, and Illustration in Appendix. [1913 Webster]