Word of apology (5)
I believe the answer is:
sorry
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">word of apology</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 sorry that I've seen before include "Showing regret" , "Contrite" , "Feeling penitent" , "My apologies!" , "I didn't quite catch that?" .)