slyly
🇺🇸
/ˈslaɪli/
🇬🇧
/ˈslaɪli/
In a sneaky or tricky way, often to deceive others.
The magician slyly switched the cards while no one was looking.
In a way that suggests you have a secret or know something others don't.
She smiled slyly, hinting at the surprise she had planned.