Of a person or an animal: sly, stealthy.
Of a thing: done with evasive or guilty secrecy.
Of a thing: that has been acquired by theft; stolen; also (generally) taken stealthily.
Of a person, etc.: inclined to steal; pilfering, thieving.
Mysterious; scheming; having a deceptive outward appearance
Like a sphinx, or like that of a sphinx. Especially, not showing emotion