underwrapped
occulted
subterranean
closehanded
mum
crypto-
on the hush
on the down-low
under the covers
secernent
hidness
under the table
secretly
darkness
masked
clandescent
cryptadia
off-the-record
covert
keep a lid on
secret
underhanded
concealment
buried
stall
closeness
private
under one's hat
concealedly
something nasty in the woodshed
cloakedly
semisecrecy
closehandedness
underhand
secretomal
hiddle
confidentiality
dark
clandestinely
hideling
semisecret
secrecy
hiddenness
covertness
pseudosecret
down low
hidingly
feign
unrevealed
underground
hugger-mugger
concealingly
semisecretive
secretomics
pent
under the rose
lean
ectocrine
secrete
hypersecretory
covertly
submarine
secretional
under wraps
secretionary
-crypt
out
crypto
let the cat out of the bag
sub rosa
backstairs
backstage
keep from
close-tiled
hiding
in petto
sensitive
supersecret
secretively
behind the scenes
sneaking
secretolysis
velation
doggo
out of sight
secretive
in hiding
hypersecretion
make known
occult
shadow
obvelation