| slight |
| snap(free, informal, casual, impulsive, unprepared) |
| stand-in(substitute, replacement, alternative, alternate, backup) |
| step(noun, support, move, action, control) |
| sub(substitute, replacement, alternative, alternate, backup) |
| supplanter(supply, agent, replacement, alternative, alternate) |
| supply(adjective, limited, brief, replacement, backup) |
| throwaway(adjective, temporary) |
| transitional |
| trick(reason, explanation, excuse, dodge, justification) |
| unfinished |
| unstable(adjective, short, limited, unpredictable, fickle) |
| unsubstantial(adjective, poor, uncertain, feeble, hesitant) |
| action(noun, move, control) |
| unarranged(spontaneous, unplanned, unpremeditated) |
| understudy(substitute, replacement, alternative, alternate, backup) |
| unrehearsed(free, informal, casual, spontaneous, offhand) |
| unsound(adjective, poor, uncertain, feeble, hesitant) |
| unstudied(free, informal, casual, impulsive, spontaneous) |
| vicar(supply, agent, replacement, alternative, alternate) |