a short coat
"She pulled her leather jacket on to keep warm while waiting for the bus in the rain."
(dentistry) dental appliance consisting of an artificial crown for a broken or decayed tooth
"tomorrow my dentist will fit me for a crown"
the outer skin of a potato
"After peeling the old ones, I scrubbed off the remaining jacket from each new potato before boiling them for dinner."
the tough metal shell casing for certain kinds of ammunition
"The ballistics expert had to carefully remove the brass jacket from each bullet before analyzing its chemical composition."
A piece of clothing worn on the upper body outside a shirt or blouse, often waist length to thigh length.
"She pulled her leather jacket closer as she stepped out into the chilly evening air."
In plain English: A jacket is a piece of clothing that covers your upper body and usually has sleeves and a front opening.
"She put on her leather jacket before stepping out into the cold wind."
Usage: Use "jacket" to refer to an outer garment like a coat or blazer that covers the torso and extends from the shoulders down to the waist or thighs. Do not use it for other types of clothing such as pants or footwear, even if they have similar names.
To enclose or encase in a jacket or other covering.
"The mechanic decided to jacket the exposed pipes to protect them from freezing temperatures."
In plain English: To jacket something means to cover it with a protective layer of material.
"She decided to jacket the potatoes before roasting them."
Usage: Do not use "jacket" as a verb to mean wearing outerwear; instead, it specifically means to enclose something in a protective covering, such as wrapping meat in bacon or placing a car in a foam shell for transport. Use this term only when describing the act of adding an external layer to an object, never when putting on clothing yourself.
The word jacket comes from the Middle French term jacquet, which was originally a small version of the Old French word jaque. It entered English as a diminutive form referring to a short outer garment.