Move like a snake (7)
I believe the answer is:
slither
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">move like a snake</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 slither that I've seen before include "Move smoothly over a surface with a twisting motion" , "Undulate" , "Quietly advance" , "Slide, slip" , "Move like a snake" .)