[jack.et] n [ME jaket, fr. MF jaquet, dim. of jaque short jacket, fr. jacque peasant, fr. the name Jacques James] (15c) 1 a: a garment for the upper body usu. having a front opening, collar, lapels, sleeves, and pockets b: something worn or fastened around the body but not for use as clothing
2. a (1): the natural covering of an animal (2): the fur or wool of a mammal b: the skin of a potato
3: an outer covering or casing: as a (1): a thermally nonconducting cover (2): a covering that encloses an intermediate space through which a temperature-controlling fluid circulates (3): a tough cold-worked metal casing that forms the outer shell of a built-up bullet b (1): a wrapper or open envelope for a document (2): an envelope for enclosing registered mail during delivery from one post office to another c (1): a detachable protective cover for a book (2): a paper or paperboard envelope for a phonograph record -- jack.et.less adj
[2]jacket vt (1856): to put a jacket on: enclose in or with a jacket