furtive

furtive [ FUR-tiv ]
[ adjective ]

MEANING :
1. surreptitious or stealth or secret
2. sly or sneaky
3. having hidden motives

USAGE EXAMPLE 1 :
Security personnel were alerted by the furtive behaviour of the thief.
USAGE EXAMPLE 2 :
The Sunday Telegraph can reveal that amid the deteriorating health of the Duke’s brother King George VI, who had succeeded him after the 1936 abdication crisis, furtive discussions began among rattled courtiers and senior politicians to the possibility of a “caretaker” monarch.