Puberty (11)
I believe the answer is:
adolescence
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">puberty</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for adolescence that I've seen before include "Period of strong growth" , "Period before adulthood" , "Transition to adulthood" , "Youthful period" , "Puberty" .)