Sermoniser (8)
I believe the answer is:
preacher
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">sermoniser</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 preacher that I've seen before include "evangelist found" , "One spreads the message" , "Religious minister" , "One giving a sermon" , "Gospeller" .)