cunning

(adj) having the skill of tricking others to achieve something

e.g. A cunning look flashed in her eyes when she realised that the old lady was gullible.

synonyms: sly, devious, scheming

(n) the skill of tricking others to achieve something

e.g. We need to show some cunning if we want to defeat the enemy.

other word forms: cunningly (adv)