furtive

adjective4

1. •
   Of a thing: done with evasive or guilty secrecy.

   • [T]ender cares and mild domestic Loves, / With furtive watch, pursue her [a swan] as she moves; […] — 1787
2. •
   Of a person or an animal: sly, stealthy.

   • All women have their foibles. Wise husbands must bear and forbear. Is that all? wherefore, then, is her aspect so furtive, wherefore on his a wild, vigilant sternness? — 1857
3. •
   Of a thing: that has been acquired by theft; stolen; also (generally) taken stealthily.
4. •
   Of a person, etc.: inclined to steal; pilfering, thieving.