Altar boy (7)
I believe the answer is:
acolyte
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">altar boy</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 acolyte that I've seen before include "Person who assists a priest" , "Religious assistant" , "Faithful assistant" , "Attendant - faithful follower" , "Devoted follower" .)