Dentition (5)
I believe the answer is:
teeth
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">dentition</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I know that dentition can be written as teeth)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for teeth that I've seen before include "they add effectiveness" , "Projections on a gear" , "Canines, maybe" , "Cog wheel projections" , "Dentition" .)