What does undershirt mean?
An undershirt is a light garment worn directly beneath another shirt or jacket. It is usually sleeveless, close-fitting, and made from cotton or another absorbent fabric, although undershirts may also be sleeved and function as warm base layers. The garment sits between the body and outer clothing, helping protect the outer layer from perspiration and providing support, insulation, or coverage. In everyday American English, “undershirt” commonly describes a plain sleeveless shirt worn under a dress shirt, especially by men, while in British English “vest” is often the more usual term. An undershirt can also mean the T-shirt worn under another shirt, although the two garments are not always interchangeable. The word is simple and transparent—“under” plus “shirt”—but the clothing has long served a practical purpose: keeping outer garments cleaner while adding a modest layer of comfort.
nounA light garment worn directly beneath a shirt or other outer layer of clothing, typically sleeveless and close-fitting. It may provide warmth, absorb perspiration, or protect the outer garment.
- A light garment worn beneath a shirt, jacket, or other outer layer, often sleeveless and close-fitting.
"He slipped on a crisp white undershirt before buttoning his blue shirt."
"He slipped on a crisp white undershirt before buttoning his blue shirt."
"She wore a thermal undershirt beneath her sweater during the hike."
The plural is formed by adding -s and is used when referring to multiple individual garments.
"The players changed into clean undershirts before taking the field."
In British English, “vest” often names the garment Americans call an undershirt—a small transatlantic vocabulary trap hiding in plain sight.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does undershirt come from?
Undershirt is a transparent English compound formed in early modern English from “under” and “shirt,” referring to a garment worn beneath another shirt. “Shirt” comes from Old English scorte, meaning “short garment,” and ultimately from a Proto-Germanic root shared with words such as skirt and the Scandinavian forms skjorta and skjorte.
How undershirt is actually used
The term is neutral and everyday. In American English it often denotes a plain sleeveless cotton shirt, especially one worn under a dress shirt; in British English, “vest” is more common. It may also refer more broadly to a warm or absorbent base layer.
Easily confused with undershirt
A T-shirt is defined by its short sleeves and neckline, whereas an undershirt is defined by being worn beneath another garment and is often sleeveless.