Felt regret (4)
I believe the answer is:
rued
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">felt regret</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for rued that I've seen before include "'Regretted, repented (4)'" , "Was sorry" , "Was contrite about" , "was remorseful" , "Bitterly regretted" .)