Be sorry for (3)
I believe the answer is:
rue
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">be sorry for</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for rue that I've seen before include "show regret" , "The 'herb of grace'" , "Be regretful" , "Feel sorry" , "way Parisians go about" .)