Forget to mention (4)
I believe the answer is:
omit
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">forget to mention</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for omit that I've seen before include "Fail (to do something)" , "Exclude; veto" , "Drop" , "Don't include" , "Exclude; forget to include" .)