(p. pr. & vb. n.) of Skulk.

back-door backstairs clandestine covert cowering cringing doggo feline furtive hidden out hidlings hole-and-corner hugger-mugger in ambush in hiding in the wings lurking on tiptoe privy prowling pussyfoot pussyfooted quailing quiet shifty slinking slinky sly sneaking sneaky stealing stealthy surreptitious under cover under-the-counter under-the-table undercover underground underhand underhanded unobtrusive waiting concealed