"a furtive manner"
"a sneak attack"
"stealthy footsteps"
"a surreptitious glance at his watch"
"backstairs gossip"
"his low backstairs cunning"
"backstairs intimacies"
"furtive behavior"
The students made furtive drawings, or passed notes.
出自: T. C. Wolfe
There was nothing furtive about his going in: he entered boldly and directly.
出自: D. Hammett