Underhand (adjective)

Not open or honest; done secretly or deceitfully.

Origin:

From the prefix under- meaning beneath or not openly and the word hand.

Examples:

1. He has an underhand way of doing things.
2. She had an underhand method of getting what she wanted.
3. The company was accused of using underhand tactics to win the contract.
4. He had an underhand way of getting out of trouble.
5. She had an underhand way of getting ahead in her career.