Nautical. a square mainsail.
the principal dish or course of a meal, typically including meat or fish.
Origin of main course
First recorded in 1505–15
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
Examples from the Web for main course
Historical Examples of main course
Towards midnight of the 20th June, the wind increased so much, that we had to lay our ship a-try all night under her main-course.
The jib and flying jib were also taken in, and a little later the main-course and the mizzen-course.At the Fall of Port Arthur
the principal dish of a meal
nautical a square mainsail
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