Unorthodox sect (4)
I believe the answer is:
cult
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">unorthodox sect</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for cult that I've seen before include "System of religious beliefs and rituals" , "Unorthodox or false religion" , "unorthodox organisation" , "Group with system of formal worship" , "Narrow religious sect" .)