Comb projection (5)
I believe the answer is:
tooth
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">comb projection</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 tooth that I've seen before include "One needed to chew" , "Fang; cog" , "Bonelike structure" , "1 across" , "In which the old are long" .)