Direct opposites:
* Dislike: This is the most direct opposite, meaning to have a negative feeling towards something.
* Disprefer: This is a less common word, but it specifically means to prefer something less than another.
Other options:
* Reject: This implies a stronger rejection, not just disliking something but actively choosing against it.
* Avoid: This suggests a desire to stay away from something, rather than simply not preferring it.
* Hate: This is a very strong word that suggests a strong aversion to something.
* Despise: Similar to hate, but often with a sense of contempt.
Specific to situations:
* Choose: If the context is about making a choice, "choose" can be an antonym if it implies choosing something *other* than what is preferred.
The best antonym for "prefer" will depend on the specific meaning and context of the sentence.