tarpaulin

noun

1. a protective covering of canvas or other material waterproofed with tar, paint, or wax.
2. a hat, especially a sailor’s, made of or covered with such material.
3. Rare. a sailor.

noun

1. a heavy hard-wearing waterproof fabric made of canvas or similar material coated with tar, wax, or paint, for outdoor use as a protective covering against moisture
2. a sheet of this fabric
3. a hat of or covered with this fabric, esp a sailor’s hat
4. a rare word for seaman

n.c.1600, from tar (n.1) + palling, from pall “heavy cloth covering” (see pall (n.)); probably so called because the canvas is sometimes coated in tar to make it waterproof.