Gnawing mammal (6)
I believe the answer is:
rodent
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">gnawing mammal</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for rodent that I've seen before include "Eg, mouse, squirrel" , "Mouse, squirrel or rat" , "A rat, for instance" , "Eg, mouse or rat" , "Rat perhaps" .)