/ ˈdʒækɪt; NAmE / noun
a 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 / tweed jacket
I have to wear a jacket and tie to work.
—see also bomber jacket , dinner jacket , donkey jacket , flak jacket , life jacket , smoking jacket , sports jacket , straitjacket
(also ˈdust jacket ) a loose paper cover for a book, usually with a design or picture on it
an outer cover around a hot water pipe, etc., for example to reduce loss of heat
( BrE ) the skin of a baked potato :
potatoes baked in their jackets
( especially NAmE ) = sleeve (3)
late Middle English : from Old French jaquet , diminutive of jaque ; origin uncertain, perhaps based on Arabic .