Person under age (5)
I believe the answer is:
minor
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">person under age</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 minor that I've seen before include "Person not yet of legal age" , "Slight; little known" , "Less important" , "Under-age or of little importance" , "Of little significance" .)