What is the meaning of Eraser?

One who erases.

An object used to erase or remove something written or drawn by a pen or a pencil.

An object used to erase something written either by chalk on a chalkboard, by a marker on a whiteboard, or by some other erasable implement; a chalkboard eraser, whiteboard eraser, etc.

An overwriter program used to prevent data recovery.

Source: wiktionary.org