slyly
adverbUK /ˈslaɪ.li/
US /ˈslaɪ.li/
In a sneaky way that is hard to notice.
She slyly slipped the extra cookie into her pocket.
OTHER MEANINGS
2. In a clever and playful way that shows you know a secret.
He smiled slyly when he guessed the surprise.
3. In a way that hides your real plan.
The fox moved slyly through the tall grass.
4. In a way that is not honest but hard to catch.
She slyly changed the rules of the game.