backspacer

from WordNet (r) 3.0 (2006)

backspacer
    n 1: the typewriter key used for back spacing [syn: {backspace
         key}, {backspace}, {backspacer}]

from The Collaborative International Dictionary of English v.0.48

backspace \backspace\, backspacer \backspacer\n.
   1. The key on a typewriter or other keyboard used for back
      spacing.

   Syn: backspace key.
        [WordNet 1.5]