furtive
[ˈfɜːɾɪv]adjective
Done secretly and quickly, as if trying to hide something or avoid being noticed.
Example sentence
- “She cast a furtive glance at the door before slipping the note into her pocket.”
Almost glued to 'glance': a furtive glance is the signature example. It implies guilt in the sneaking; 'stealthy' can be neutral, furtive rarely is.