[ meyn-seyl; Nautical meyn-suhl ]

  1. the lowermost sail on a mainmast.

Origin of mainsail

late Middle English word dating back to 1425–75; see origin at main1, sail

Words Nearby mainsail Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use mainsail in a sentence

  • What they saw was the yacht Eagle, not far from the bluff, under full mainsail, standing out of the cove.

    The Rival Campers | Ruel Perley Smith
  • Moreover, although she carried an enormous club-topsail and a mainsail of big area, she heeled over the least of any of the boats.

    The Rival Campers | Ruel Perley Smith
  • Then he proceeded to untie the stops in the mainsail, and was thus engaged when a voice hailed him from the shore.

    The Rival Campers | Ruel Perley Smith
  • The size of the jib is also influenced by the fact that it has to balance the equally enormous mainsail.

    Yachting Vol. 2 | Various.
  • In reefing the mainsail is accessible, and the absence of the long boom of the cat-boat is readily appreciated.

    Yachting Vol. 2 | Various.

British Dictionary definitions for mainsail


/ (ˈmeɪnˌseɪl, nautical ˈmeɪnsəl) /

  1. nautical the largest and lowermost sail on the mainmast

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012