Drop or sink (7)
I believe the answer is:
descend
<span class="explanation-format__ClueExplanation">I believe this is a double definition.<br/ ><br/ >'<span class="explanation-format__original">drop</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I know that drop is a more specific form of the action descend)</span><br/ ><br/ >'<span class="explanation-format__original">sink</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I know that sink is a more specific form of the action descend)</span><br/ ><br/ ></span>
(Other definitions for descend that I've seen before include "Move downwards" , "Plunge" , "Come down" , "Climb down" , "Move downward" .)