| surrogate(noun, agent, substitute, replacement, representative) |
| understudy(noun, guide, reserve, replacement, nurse) |
| vassal(noun, servant) |
| admirer |
| advocate(noun, representative, manager, mediator) |
| analyst(noun, hand, servant, worker, employee) |
| ancilla(noun, hand, subsidiary, worker, employee) |
| appurtenant(adjective, spare, minor, helpful, secondary) |
| assignee(noun, representative, operative, manager, deputy) |
| booster |
| clerk(noun, help, agent, representative, attendant) |
| co-worker(noun, guide, associate, supporter, friend) |
| coadjutrix |
| collateral(adjective, help, spare, minor, helpful) |
| contributory(adjective, help, spare, minor, helpful) |
| dummy(noun, replacement, alternative, alternate, deputy) |
| extra(noun, spare, auxiliary) |
| factor(agent, representative, operative, manager, deputy) |
| functionary(noun, representative, operative, manager, deputy) |
| instructor(associate, principal, coach, member, fellow) |