Ovum (3)
I believe the answer is:
egg
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">ovum</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I know that egg is a type of ovum)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for egg that I've seen before include "nit? Just a bit!" , "Over-easy breakfast item?" , "Poached or boiled?" , "explosive" , "Early stage of development" .)