| furtive(adjective, obscure, unknown, underground, sneaky) |
| secret(adjective, hidden, clandestine, underground, undisclosed) |
| conspirative |
| surreptitious(adjective, clandestine, underground, sneaky, covert) |
| artful(adjective, sneaky, covert, secretive) |
| clandestine(adjective, underground, undisclosed, sneaky, covert) |
| collusive |
| covert(adjective, clandestine, underground, undisclosed, sneaky) |
| partisan(adjective, collateral, interested, prejudiced, subsidiary) |
| private(adjective, obscure, unknown, clandestine, underground) |
| scheming(adjective, sneaky, covert, secretive) |
| secretive(adjective, clandestine, underground, undisclosed, sneaky) |
| shifty(adjective, sneaky, covert, secretive) |
| underhand(adjective, clandestine, underground, undisclosed, sneaky) |
| concomitant(adjective, collateral, subsidiary, subservient, subalternate) |
| concordant(adjective, collateral, subsidiary, subservient, subalternate) |
| creepy(adjective, sneaky, covert, secretive) |
| esoteric(adjective, obscure, unknown, clandestine, underground) |
| evasive(adjective, sneaky, covert, secretive) |
| knowing |