widget An element of a user interface that behaves in a particular way. The term is associated with the X Windows system, where a widget in general corresponds to an X window together with the functions and rules that determine its input and output behavior. Examples of widgets include buttons and scroll bars. Widgets are therefore components from which user interfaces can be constructed. Different widget sets are available on X windows and these provide the elements for constructing user interfaces. Different widget sets will usually provide different styles of interface.

widg·et / ˈwijit/ • n. inf. a small gadget or mechanical device, esp. one whose name is unknown or unspecified. ∎  Comput. a component of a user interface that operates in a particular way.