Rummage (5)
I believe the answer is:
delve
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">rummage</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 delve that I've seen before include "Make painstaking enquiries (into something)" , "probe deeply" , "Intensively research (into something)" , "Dig - rummage" , "Look closely (into)" .)