1620s, caskette, originally nautical, "small rope or plaited coil" used to secure a furled sail, of uncertain origin, perhaps from French garcette "a gasket," literally "little girl, maidservant," diminutive of Old French garce "young woman, young girl; whore, harlot, concubine" (13c.), fem. of garçon (see garcon). Century Dictionary notes Spanish garcette "a gasket," also "hair which falls in locks." Machinery sense of "packing (originally of braided hemp) to seal metal joints and pistons" first recorded 1829.