furtive

adjectives

marked by quiet and caution and secrecy; taking pains to avoid being observed

"a furtive manner"; "a sneak attack"; "stealthy footsteps"; "a surreptitious glance at his watch"

furtive, sneak, sneaky, stealthy, surreptitious

is derived from

secret and sly or sordid

"backstairs gossip"; "his low backstairs cunning"- A.L.Guerard; "backstairs intimacies"; "furtive behavior"

backstair, backstairs, furtive

is derived from