Paternity (10)
I believe the answer is:
fatherhood
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">paternity</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I know that paternity can be written as fatherhood)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for fatherhood that I've seen before include "Paternity" , "old man" , "responsibility over issue" .)