an area of canvas or other fabric extended to the wind in such a way as to transmit the force of the wind to an assemblage of spars and rigging mounted firmly on a hull, raft, iceboat, etc., so as to drive it along.
some similar piece or apparatus, as the part of an arm that catches the wind on a windmill.
a voyage or excursion, especially in a sailing vessel:
They went for a sail around the island.
a sailing vessel or ship.
sailing vessels collectively:
The fleet numbered 30 sail.
sails for a vessel or vessels collectively.
(initial capital letter) Astronomy. the constellation Vela.
O.E. segl, from P.Gmc. *seglom (cf. Swed. segel, O.N. segl, O.Fris. seil, Du. zeil, O.H.G. segal, Ger. Segel), of obscure origin with no known cognates outside Gmc. Ir. seol, Welsh hwyl "sail" are Gmc. loan-words. Sometimes referred to PIE root *sek- "to cut," as if meaning "a cut piece of cloth." The verb is O.E. segilan, from the same Gmc. source (cf. O.N. sigla, M.L.G. segelen, Ger. segeln).