1. Playful in an appealingly bold way; SYN. rascally, roguish.
2. Showing the cunning or ingenuity or wickedness typical of a devil; SYN. diabolic, diabolical, mephistophelian, mephistophelean.
In a playfully devilish manner; SYN. devilish.
Diabolically; wickedly, maliciously; like a demon