Answer: sliest

AnswerCrossword Clue
SLIEST

Like the best ruse

SLIEST

Most deceitful.

SLIEST

Most conniving.

SLIEST
Most roguish.
SLIEST
Shrewdest.
SLIESTWiliest
SLIESTMost tricky
SLIESTMost wily
SLIESTMost foxy
SLIESTMost clever
SLIESTMaximally cunning
SLIESTMost foxy.
SLIESTLike the fox among all beasts
SLIESTLike the chief fox
SLIESTHardest to outwit
SLIESTLeast straightforward
SLIESTMost furtive
SLIESTCrafty to the max
SLIESTTops in cunning
SLIESTThe most conniving
SLIESTMost cagey
SLIESTMost canny
SLIESTMost underhanded
SLIESTMost foxlike
SLIESTFoxiest
SLIESTMost conniving
SLIESTMost cunning
SLIESTMost crafty
SLIESTLeast candid
SLIESTMost artful
SLIESTMost devious
SLIESTSuperlatively foxy
SLIESTSuperlatively surreptitious
SLIESTMost roguish
SLIESTMost dodgy
SLIESTLeast honest
SLIESTArtful to the max
SLIESTMost guileful
SLIESTLeast forthright
SLIESTCraftiest.