devious
Sneaky and tricky in a secret, dishonest way.
Devious means using sneaky, underhanded methods to get what you want. A devious person works through trickery, deception, and clever manipulation to achieve their goals while hiding their true intentions.
If a student creates a devious plan to avoid doing homework, they might fake being sick, forge a note, or create an elaborate excuse involving a story about their dog. The key feature of devious behavior is that it's calculated and secretive, involving deliberate planning rather than impulsive dishonesty.
The word often describes schemes or plots. A devious villain in a story might set traps, plant false clues, or manipulate others into doing their dirty work. When someone follows a devious route, they're taking a winding, indirect path, literally or figuratively, perhaps to avoid being followed or to hide their intentions.
While cleverness itself is admirable, devious carries a negative connotation because it implies using intelligence for dishonest purposes. Someone might call a complicated scam a devious scheme or describe a manipulative person as having a devious mind.