backspace key vs backspacer

backspace key and backspacer both are nouns.

Word	Noun	Adjective	Verb	Adverb
backspace key	Yes	No	No	No
backspacer	Yes	No	No	No

As nouns, backspace key and backspacer are synonyms defined as:

Other synonyms of backspace key include backspace.

backspace key (noun)	backspacer (noun)
the typewriter key used for back spacing	the typewriter key used for back spacing