Butterfingers' cry (4)
I believe the answer is:
oops
'butterfingers' cry' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for oops that I've seen before include "Oh dear, that was careless!" , "Oh dear, that's a mistake!" , "Exclamation recognising a mistake has been made" , "Something's been spilt!" , "Harem" .)