Webster defines dungaree as "a coarse kind of fabric worn by the poorer class of people and also used for tents and sail." I find it hard to picture my favorite pair of dungarees flying from the mast of a sailing ship, but in those days Sailors often made both their working clothes and hammocks out of discarded sail cloth.
The 1901 Navy regulations authorized the first use of denim jumpers and trousers, and the 1913 regulations originally permitted the dungaree outfit to be used by both officers and enlisted with the hat of the day. The cloth used then was not as well woven as it is today, nor was it dyed blue, but it served the purpose. Dungarees worn by Sailors of the Continental Navy were cut directly from old sails and remained tan in color just as they been when filled with wind. After battles, it was the practice in both the American and British Navies for Captains to report more sail lost in battle than actually was the case so the crew would have cloth to mend their hammocks and make new clothes. Since the cloth was called dungaree, clothes made from the fabric borrowed the name.