Roman Catholic prince (8)
I believe the answer is:
cardinal
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">roman catholic prince</span>' is the definition.<br/ ><span class="explanation-format__explanation">(leading dignitary of the Roman Catholic Church)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for cardinal that I've seen before include "Prince of the Roman Catholic Church" , "High-ranking official of the Roman Catholic church" , "of prime importance" , "Main - church dignitary" , "Principal - churchman" .)