* Copy: If you're talking about something being unique and not a copy, the opposite is a copy.
* Imitation: This is similar to a copy but implies a deliberate attempt to reproduce something else.
* Derivative: This suggests something is based on something else and isn't truly new or original.
* Uninspired: This means lacking originality or creativity.
* Conventional: This describes something that follows established norms and lacks originality.
* Commonplace: This means something is ordinary and not special or original.
The best opposite will depend on the specific situation and what you're trying to express.