Definition of jacket
- jacket Noun A piece of clothing worn on the upper body outside a shirt or blouse, often waist length to thigh length.
- jacket Noun A piece of a person suit, beside trousers and, sometimes, waistcoat ; coat
- jacket Noun A removable or replaceable protective or insulating cover for an object (eg a book, hot water tank.)
- jacket Noun A police record.
- jacket Verb To enclose or encase in a jacket or other covering.