I.e., toils roughly - most unctuous (7)
I believe the answer is:
oiliest
'most unctuous' is the definition.
(I've seen this before)
'i e toils roughly' is the wordplay.
'roughly' indicates an anagram.
'i'+'e'+'toils'='ietoils'
'ietoils' with letters rearranged gives 'OILIEST'.
(Other definitions for oiliest that I've seen before include "Most unctuous" , "Most greasy" , "Most flattering" .)