An eraser is an object, usually a piece of rubber or plastic, which is used for removing something that has been written using a pencil or a pen.
[US, also British, formal]
...a large, flat, pink India-rubber eraser.
eraser in British English
(ɪˈreɪzə)
noun
an object, such as a piece of rubber or felt, used for erasing something written, typed, etc
a pencil eraser
eraser in American English
(iˈreɪsər; ɪˈreɪsər)
noun
a thing that erases; specif., a device made of rubber for erasing ink or pencil marks, or a pad of felt or cloth for removing chalk marks from a blackboard