Bicuspid eg (5)
I believe the answer is:
tooth
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">bicuspid eg</span>' is the definition.<br/ ><span class="explanation-format__explanation">(bicuspid is a kind of tooth)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for tooth that I've seen before include "One needed to chew" , "It erupts" , "Fang; cog" , "Eg, molar" , "1 across" .)