Onearmed

Onearmed, often written as one-armed, is an English adjective and noun used to describe a person or object that has a single arm. When referring to people, it denotes someone with one upper limb due to congenital limb absence or amputation. In modern usage, many style guides favor person-first language, such as “a person with one arm,” rather than labeling someone as “one-armed.” As a descriptor, it can be neutral or potentially stigmatizing depending on context and tone.

In addition to its human reference, the term applies to devices or mechanisms that feature a single arm or lever. The most familiar usage is in the phrase one-armed bandit, a nickname for slot machines. The name stems from early mechanical machines that required pulling a single vertical lever, or arm, to start a game. Although contemporary slot machines often use buttons rather than manual levers, the historical term remains in common parlance.

Other uses of the term may appear in technical descriptions of robotics, cranes, or other apparatus that employ a lone articulated arm. In these contexts, one-armed conveys a simple, descriptive contrast with multi-armed configurations.

See also: Amputation, Prosthesis, Disability terminology, One-armed bandit.