Teen (10)
I believe the answer is:
adolescent
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">teen</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for adolescent that I've seen before include "At the stage between childhood and maturity" , "Young person" , "Youngster" , "juvenile" , "Teenager" .)