the lowermost sail on a mainmast.
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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.
Moreover, although she carried an enormous club-topsail and a mainsail of big area, she heeled over the least of any of the boats.
Then he proceeded to untie the stops in the mainsail, and was thus engaged when a voice hailed him from the shore.
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
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