- 1a piece of clothing worn on the top half of the body over a shirt, etc. that has sleeves and fastens down the front; a short, light coat a denim/wool jacket I have to wear a jacket and tie to work. see bomber jacket, dinner jacket, flak jacket, life jacket, smoking jacket, sports jacket, straitjacket
- 2(also dust jacket) a loose paper cover for a book, usually with a design or picture on it
- 3an outer cover around a hot water pipe, etc., for example to reduce loss of heat
- 4(also sleeve) a stiff paper envelope for a record a colorful jacket design
Check pronunciation: jacket