cryptadia
keep a lid on
keep from
concealment
under wraps
concealing
hiding
secret
hush up
stall
on the down-low
under the covers
closet
secretiveness
secrecy
silence
darkness
on the hush
subterranean
closehanded
keep shady
secernent
underwrapped
keep quiet
ultrasecret
let the cat out of the bag
hidness
lie low
sensitive
occulted
behind the scenes
confidentiality
backstage
sub rosa
hiddle
obvelation
conceal
feign
shoot off at the mouth
lean
secrete
under the table
off-the-record
hypersecrecy
under one's hat
closeness
on the QT
confidence
on the Q.T.
secretly
in secret
undisclosed
something nasty in the woodshed
cloakedly
secretomics
keep one's lips sealed
out
pseudosecret
shadow
exposure
leak out
covert
closehandedness
crypto-
concealedly
mum
close-tiled
dark
make known
occult
semisecrecy
in petto
masked
tick a lock
yield up
secretive
spill the beans
underhand
confidential
confide
clandescent
abscond
mum's the word
pent
clandestinely
under the rose
backroom
undisclosedly
hugger-mugger
open secret
keep
private
break