Slide; undergarment (4)
I believe the answer is:
slip
<span class="explanation-format__ClueExplanation">I believe this is a double definition.<br/ ><br/ >'<span class="explanation-format__original">slide</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I know that slide can be written as slip)</span><br/ ><br/ >'<span class="explanation-format__original">undergarment</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(slip is a kind of undergarment)</span><br/ ><br/ ></span>
(Other definitions for slip that I've seen before include "Minor mistake - undergarment" , "Underwear" , "One on cricket field" , "Clay, water mix; fielder" , "Strip" .)