Tar, Jack Tar
Tar, a slang term for a Sailor, has been in use since at least 1676. The term "Jack tar" was used by the 1780s. Early Sailors wore overalls and broad-brimmed hats made of tar-impregnated fabric called tarpaulin cloth. The hats, and the Sailors who wore them, were called tarpaulins, which may have been shortened to tars.