Most luxuriant (7)
I believe the answer is:
lushest
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">most luxuriant</span>' is the definition.<br/ ><span class="explanation-format__explanation">('lush' can be a synonym of 'luxuriant')</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for lushest that I've seen before include "Most luxurious in growth" , "Most profuse or succulent" , "Most luxuriant" , "Most juicy" , "Most fleshy" .)