| ancillary(adjective, collateral, subsidiary, subservient, subalternate) |
| appurtenant(adjective, collateral, subsidiary, subservient, subalternate) |
| arcane(adjective, obscure, unknown, clandestine, underground) |
| associated with(expression, adjective, collateral, subsidiary, subservient) |
| associative(adjective, collateral, subsidiary, subservient, subalternate) |
| attendant(adjective, collateral, subsidiary, subservient, subalternate) |
| auxiliary(adjective, collateral, subsidiary, subservient, subalternate) |
| backstairs(clandestine, underground, undisclosed) |
| barely moving |
| below the mark(expression, adjective, idiom, collateral, subsidiary) |
| bent |
| calculated to produce(expression, adjective, idiom, collateral, subsidiary) |
| classified(adjective, obscure, unknown, clandestine, underground) |
| cloak and dagger(expression, idiom, obscure, unknown, unrevealed) |
| cloaked(adjective, sneaky, covert, secretive) |
| closet(adjective, obscure, unknown, clandestine, underground) |
| coefficient(adjective, collateral, subsidiary, subservient, subalternate) |
| collateral(adjective, subsidiary, subservient, subalternate, cliquish) |
| conducive(adjective, collateral, subsidiary, subservient, subalternate) |
| confidential(clandestine, underground, undisclosed) |