| substitute(noun, reserve, alternative, someone, something) |
| alternate(noun, replacement, alternative, backup, surrogate) |
| stand-in(noun, reserve, replacement, alternative, alternate) |
| backup(noun, reserve, replacement, alternative, alternate) |
| sub(noun, reserve, substitute, replacement, alternate) |
| understudy(noun, reserve, substitute, replacement, stalwart) |
| agent(replacement, alternative, alternate, backup, surrogate) |
| alternative(noun, replacement, alternate) |
| assistant(reserve, replacement, alternative, alternate, backup) |
| auxiliary(replacement, alternative, alternate, backup, surrogate) |
| changeling(replacement, alternative, alternate, backup, surrogate) |
| delegate(replacement, alternative, alternate, backup, surrogate) |
| deputy(noun, reserve, replacement, alternative, alternate) |
| dernier ressort(expression, replacement, alternative, alternate, backup) |
| double(noun, reserve, substitute, replacement, alternate) |
| dummy(replacement, alternative, alternate, backup, surrogate) |
| equivalent(replacement, alternative, alternate, backup, surrogate) |
| expediency(replacement, alternative, alternate, backup, surrogate) |
| expedient(replacement, alternative, alternate, backup, surrogate) |
| fill-in(reserve, replacement, alternative, alternate, backup) |