| covert(adjective, show, secret, hidden, clandestine) |
| undercover(adjective, show, dishonest, secret, hidden) |
| hush-hush(adjective, show, dishonest, secret, hidden) |
| secret(adjective, show, dishonest, hidden, clandestine) |
| ulterior(adjective, cover, obscure, secret, hidden) |
| underground(adjective, secret, hidden, spy, clandestine) |
| clandestine(adjective, show, dishonest, secret, hidden) |
| furtive(adjective, dishonest, secret, hidden, clandestine) |
| hidden(secret, clandestine, underground, sneaky, covered) |
| top secret(noun, expression, sensitive, clandestine, underground) |
| abstruse(clandestine, underground, undisclosed) |
| arcane(clandestine, underground, undisclosed) |
| buried(cover, obscure, dark, secret, hidden) |
| classified(sensitive, secret, clandestine, underground, undisclosed) |
| cloak-and-dagger(adjective, show, secret, hidden, clandestine) |
| close(clandestine, underground, undisclosed) |
| clouded(clandestine, underground, undisclosed) |
| concealed(obscure, dark, dishonest, secret, hidden) |
| covered(secret, hidden, clandestine, underground, undisclosed) |
| cryptic(cover, obscure, dark, equivocal, clandestine) |