Fail to include (4)
I believe the answer is:
omit
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">fail to include</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 omit that I've seen before include "Don't include" , "Exclude; forget to include" , "Fail to include" , "Drop" , "Leave out or overlook" .)