furtive
/ˈfər-tiv/
adjective
done in a quiet and secretive way to avoid being noticed : surreptitious
expressive of stealth : sly
obtained underhandedly : stolen
a furtive glance
had a furtive look about him
secret covert stealthy furtive clandestine surreptitious underhanded mean done without attracting observation. secret implies concealment on any grounds for any motive. covert stresses the fact of not being open or declared.