Attic
aesthetic
artistic
back-door
backstairs
chaste
choice
clandestine
classic
covert
excellent
feline
furtive
hidlings
hole-and-corner
hugger-mugger
humble
in good taste
meek
modest
of choice
of quality
pleasing
privy
pure
quiet
restrained
shifty
simple
skulking
slinking
slinky
sly
sneaking
sneaky
stealthy
subdued
surreptitious
tasteful
tasty
unaffected
unambitious
unaspiring
unassuming
unboastful
under-the-counter
under-the-table
undercover
underground
affable
cordial
discreet
disinterested
persuasive
respectful
sober
straightforward
tranquil
unpretentious
well-behaved
womanly
abusive
allusive
collusive
conclusive
conducive
elusive
exclusive
illusive
inclusive
inconclusive
intrusive
nonexclusive
obtrusive
reclusive