abstruse
activity
adventure
affair
aim
ambiguous
arcane
assignment
baby
blueprint
business
camouflaged
classified
cloakanddagger
close
closet
concept
concern
confidential
covered
covert
cryptic
dark
deal
deep
design
designing
disguised
draft
enterprise
esoteric
exploit
feat
furtive
grunge
grungy
hidden
hushhush
ink
intention
job
matter
miscellaneous
mysterious
mystic
mystical
obscure
occult
occupation
outline
outoftheway
pet
plan
private
program
project
projection
proposal
proposition
rectangular
red
rubber
scheme
secluded
secret
setup
sign
stamp
strategy
symbol
task
text
thing
undercover
underground
undisclosed
unknown
unlisted
unseen
venture