Wished undone (4)
I believe the answer is:
rued
'wished undone' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for rued that I've seen before include "Was contrite about" , "Was sorry" , "'Regretted, repented (4)'" , "was remorseful" , "Bitterly regretted" .)