Coyly roguish (4)
I believe the answer is:
arch
'coyly roguish' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for arch that I've seen before include "Curved entrance" , "Chief - supporter - cunning" , "Roguish - superior" , "Affectedly playful like senior angel" , "Teasing; part of foot" .)