1.
A ~ look, expression, or remark shows that you know something that other people do not know or that was meant to be a secret.
His lips were spread in a ~ smile...
ADJ: usu ADJ n
~ly
Anna grinned ~ly.
ADV
2.
If you describe someone as ~, you disapprove of them because they keep their feelings or intentions hidden and are clever at deceiving people.
She is devious and ~ and manipulative...
= cunning
ADJ disapproval