One using teeth (5)
I believe the answer is:
biter
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">one using teeth</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 biter that I've seen before include "One may snap" , "Someone using their teeth" , "Craftsman" , "He who is sometimes bit" , "One cutting" .)