Miss the mark (3)
I believe the answer is:
err
'miss the mark' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for err that I've seen before include "Go astray" , "Make mistake in Canberra" , "Boob" , "'To . . . is human, to forgive divine'" , "Drop a clanger" .)