Pointed remark
I believe the answer is:
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">pointed remark</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for barb that I've seen before include "part of a habit" , "Kind of thorn or wounding remark" , "Hurtful comment" , "Cruel remark" , "Arrow projection" .)