Most unctuous (7)
I believe the answer is:
oiliest
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">most unctuous</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for oiliest that I've seen before include "Most flattering" , "Most unctuous" , "Most greasy" .)