More weighty (7)
I believe the answer is:
heavier
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">more weighty</span>' is the definition.<br/ ><span class="explanation-format__explanation">('heavy' can be a synonym of 'weighty')</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for heavier that I've seen before include "Having greater weight" , "More tedious" , "Less light" , "with extra authority" , "comparatively bulky" .)