Keyboard goof (4)
I believe the answer is:
typo
'keyboard goof' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for typo that I've seen before include "Printing error (colloq.)" , "False character" , "Small keyboarding error" , "Misprint" , "Literal error in printed matter, in short" .)