What is "armbinder"

n. (context BDSM English) A restraint that binds the arms together into a single sleeve.

An armbinder is a type of restraint devices primarily used in bondage play (rather than law enforcement, medicine, or psychiatry), designed to bind the arms and/or hands to each other or to the body, usually behind the back, and employing a range of bondage equipment including cuffs, rods, straps, and gloves.

One type of armbinder is the monoglove.