Alexander Dyce, A General Glossary to Shakespeare's Works

course “or two—Up with a,” THE TWO NOBLE KINSMEN, iii. 4. 10 ; “set her two courses!” THE TEMPEST, i. 1. 46. On the second of these passages Holt observes: “The courses meant in this place are two of the three lowest and largest sails of a ship, which are so called, because, as largest, they contribute most to give her way through the water, and consequently enable her to feel her helm, and steer her course better, than when they are not set or spread to the wind.” Holt's Attempte to rescue that aunciente English Poet and Play-wrighte, etc.