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
dodging
escape
evasion
alter-ego
camping-out
chronometrical
cretur
cutting-out
eaglet
ferociousness
filibustering
greely
mma
mollycoddle
nightbird
paleface
pearl-fishing
pearling
reconnoitring
scalping
slave-making
staghound
transcontinental
tyrannosaur
well-concerted