Of great weight (5)
I believe the answer is:
heavy
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">of great weight</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 heavy that I've seen before include "Stodgy; difficult" , "Weighty - ponderous" , "Oppressive" , "Mosque prayer leader" , "Difficult to lift" .)