Small mouselike mammal (5)
I believe the answer is:
shrew
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">small mouselike mammal</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for shrew that I've seen before include "Small insectivore" , "Insectivorous mammal" , "Small mouselike animal" , "Shakespeare: 'The Taming of the ....'" , "Scold; insectivore" .)