fur ‧ tive /ˈfɜːtɪv $ ˈfɜːr-/ BrE AmE adjective
[ Date: 1600-1700 ; Language: French ; Origin: furtif , from Latin fur 'thief' ]
behaving as if you want to keep something secret SYN secretive :
There was something furtive about his actions.
furtive glances/looks
Chris kept stealing furtive glances at me.
—furtively adverb :
She opened the door and looked furtively down the hall.
—furtiveness noun [uncountable]