| slippery(adjective, dishonest, cunning, deceitful, dubious) |
| under-the-table(adjective, secret, private, hidden, clandestine) |
| underground(adjective, obscure, secret, unknown, hidden) |
| backstair |
| calculating(adjective, mean, smooth, cunning, knowing) |
| cautious(adjective, mysterious, private, reticent, sneaky) |
| close(adjective, secret, concealment, sneaky, stealthy) |
| hole-and-corner(secret, private, hidden, spy, sneaky) |
| slinking(adjective, secret, private, hidden, sneaky) |
| arcane(adjective, obscure, strange, secret, unknown) |
| buttoned up(verb, adjective, phrasal verb, secret, concealment) |
| cagey(adjective, secret, sneaky, stealthy) |
| confidential(adjective, secret, hidden, spy, clandestine) |
| cryptic(adjective, close, obscure, strange, reticent) |
| disguised(adjective, secret, hidden, clandestine, sneaky) |
| false(adjective, dishonest, cunning, unpredictable, fickle) |
| indirect(dishonest, cunning, deceitful, sly, devious) |
| latent(adjective, secret, sneaky, stealthy) |
| lurking |
| mystical(obscure, strange, unknown, clandestine, underground) |