Flow out (3)
I believe the answer is:
ebb
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">flow out</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 ebb that I've seen before include "Not to wax" , "Initially Mrs Browning's" , "Fall back" , "Abate" , "Flow back or recede" .)