| optional(adjective, useless, worthless, unwarranted, possible) |
| accidental(adjective, useless, worthless, unwarranted, unnecessary) |
| avoidable(adjective, useless, worthless, unwarranted, unnecessary) |
| facultative(adjective, open, free, voluntary, elective) |
| fortuitous(adjective, useless, worthless, unwarranted, unnecessary) |
| futile(adjective, useless, worthless, unwarranted, unnecessary) |
| noncompulsory(open, free, worthless, pointless, irrelevant) |
| uncalled-for(adjective, unwarranted, unnecessary, pointless, superfluous) |
| unneeded(adjective, useless, worthless, unwarranted, unnecessary) |
| unwanted(adjective, useless, unwarranted, unnecessary, unjustified) |
| alternative(open, free, voluntary, elective) |
| arbitrary(open, free, voluntary, elective) |
| discretionary(open, free, voluntary, elective) |
| elective(open, free, voluntary) |
| extra(open, free, voluntary, elective) |
| free(open, voluntary, elective) |
| gratuitous(unwarranted, pointless, superfluous, unjustified, undeserved) |
| impertinent(unwarranted, unjustified, undeserved) |
| inappropriate(adjective, useless, unwarranted, unnecessary, unjustified) |
| indecorous(unwarranted, unjustified, undeserved) |