| uncompelled(adjective, free, deliberate, natural, willing) |
| unrequired(adjective, casual, useless, extra, worthless) |
| unrestricted(adjective, possible, voluntary, elective) |
| autonomous(adjective, free, deliberate, natural, willing) |
| deliberate(adjective, free, natural, willing, charitable) |
| gratuitous(adjective, free, deliberate, natural, casual) |
| independent(adjective, free, deliberate, natural, willing) |
| inessential(adjective, extraordinary, new, spare, fresh) |
| intended(adjective, free, deliberate, natural, willing) |
| intentional(adjective, free, deliberate, natural, willing) |
| noncompulsory(adjective, extra, worthless, possible, pointless) |
| option |
| perk(adjective, extraordinary, new, spare, fresh) |
| spare(adjective, extraordinary, new, fresh, special) |
| unasked(adjective, free, deliberate, natural, willing) |
| unbidden(adjective, free, deliberate, natural, willing) |
| unessential(adjective, casual, useless, extra, worthless) |
| uninvited(adjective, useless, unwarranted, unnecessary, unjustified) |
| unneeded(adjective, extraordinary, new, spare, fresh) |
| unprompted(natural, spontaneous, voluntary) |