TOPSAIL Meaning of TOPSAIL in English [top.sail] also top.s'l n (14c) 1: the sail next above the lowermost sail on a mast in a square-rigged ship 2: the sail set above and sometimes on the gaff in a fore-and-aft rigged ship Merriam-Webster English vocab. Английский словарь Merriam Webster. 2012