sunyi

Behaving or speaking in a way that is indirectly rude, insulting, or disrespectful, often while pretending to be polite.

Using clever but dishonest methods; likely to trick or deceive other people.

Clever at hiding your real intentions and using secret or indirect methods, often to trick or outsmart people.

Done in a quiet, hidden way so that other people, especially people in authority, will not notice, often because it is wrong or not allowed.

Done in a secret and stealthy way to avoid being noticed or discovered, especially because it is not allowed or is disapproved of.

Quietly secretive and trying not to attract attention, especially when describing looks, smiles, or small movements.