Definition of: jacket

(jak′it) noun
1. A short coat, usually not extending below the hips.
2. Anything resembling a jacket.
3. A covering for a steam cylinder, to prevent radiation of heat.
4. A removable paper wrapper or cover for a bound book.
5. An open envelope or folder, used for filing letters, documents, papers, etc.
6. A covering of hard metal on a bullet or shell.
7. The skin of a potato.
—v.t. To cover with a jacket. [<OF jaquette, dim. of jaque a coat]
—jack′et·ed adjective