A jacket is a garment for the upper body, usually extending below the hips. A jacket typically has sleeves, and fastens in the front or slightly on the side. A jacket is generally lighter, tighter-fitting, and less insulating than a coat, which is outerwear. Some jackets are fashionable, while others serve as protective clothing. Jackets without sleeves are vests.
The word jacket comes from the French word jaquette. The term comes from the Middle French noun jaquet, which refers to a small or lightweight tunic. In Modern French, jaquette is synonymous with jacket. Speakers of American English sometimes informally use the words jacket and coat interchangeably. The word is cognate with Spanish jaco and Italian giacca or giacchetta, first recorded around 1350s. It is ultimately loaned from Arabic shakk (شكّ), which in turn loaned from Aramean/Assyrian and Hebrew shaḳḳ (שַׁקּ).