Celtic priest (5)
I believe the answer is:
druid
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">celtic priest</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 druid that I've seen before include "Ancient Celt priest" , "Pre-Christian Celtic priest" , "Ancient Celtic priest" , "Ancient priest of Wales" , "An Eisteddfod official" .)