mainsail

Definitions of mainsail
1

n the lowermost sail on the mainmast

Types:
main course
a square mainsail
Type of:
canvas, canvass, sail, sheet
a large piece of fabric (usually canvas fabric) by means of which wind is used to propel a sailing vessel

Sign up, it's free!

Whether you're a student, an educator, or a lifelong learner, Vocabulary.com can put you on the path to systematic vocabulary improvement.