eraser

n. person or thing which erases or rubs out

An eraser or rubber is an article of stationery that is used for removing pencil and sometimes pen writings. Erasers have a rubbery consistency, and they are often white, brown or pink although with modern materials they can be of any color. Many pencils are equipped with an eraser on one end. Typical erasers are made of rubber, but more expensive or specialized erasers can also contain vinyl, plastic, or gum-like materials.
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(n.)
One who, or that which, erases; esp., a sharp instrument or a piece of rubber used to erase writings, drawings, etc.
  

Noun
1. an implement used to erase something
(hypernym) implement
(hyponym) blackboard eraser
(derivation) erase, rub out, score out, efface, wipe off