Adjective
The word is derived from wily
In matching your wits against yourself you take on the shrewdest and wiliest antagonist you can have, and consequently a victorious outcome in this duel of wits brings a great feeling of triumph. Dorothea Brande
With felonious foes lined up for revenge, like the venomous Black Widow, chilling Mr. Freeze and cagey Penguin, Batman (Adam West) and Robin (Burt Ward) must match wits with the wiliest. Source: Internet
Welcome to Yosemite, iconic American landscape, hikers' paradise, and all-you-can-eat home of the wiliest bruins on earth. Source: Internet