Roguish (8)
'roguish' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for arch that I've seen before include "Chief - supporter - cunning" , "Cunning; playful" , "Mysterious - curve" , "Mischievous - shrewd" , "Curved bony structure in the foot" .)
'roguish' is the definition.
(I know that roguish can be written as rascally)
This is the entire clue.
(Another definition for rascally that I've seen is " Mischievous".)