Most malodorous (9)
I believe the answer is:
smelliest
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">most malodorous</span>' is the definition.<br/ ><span class="explanation-format__explanation">('smelly' can be similar in meaning to 'malodorous')</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for smelliest that I've seen before include "Most noisome" , "High as can be" .)