Swallow up or submerge (6)
I believe the answer is:
engulf
<span class="explanation-format__ClueExplanation">This clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">swallow up</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >'<span class="explanation-format__original">submerge</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ ></span>
(Other definitions for engulf that I've seen before include "Bury" , "Overwhelm; cover totally" , "Swallow up like wave" , "Swamp, overwhelm" , "Completely overwhelm" .)