What is the word opposite of fair?

The opposite of "fair" depends on the context. Here are a few possibilities:

If you're talking about fairness:

* Unfair is the most direct opposite.

* Unjust

* Biased

* Partial

* Unequal

* Dishonest

If you're talking about a fair (a type of amusement park):

* Carnival (though this isn't a perfect opposite, it's similar)

If you're talking about the weather:

* Stormy

* Cloudy

* Rainy

If you're talking about someone's complexion:

* Dark

* Pale

Please provide more context if you want a more specific answer!