Childhood companion (8)
I believe the answer is:
playmate
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">childhood companion</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for playmate that I've seen before include "Recreational friend" , "Chum in recreation" , "Child's friend" , "fun chum" , "Companion for fun" .)