Fair, just, honest, unprejudiced...The opposite of unfair is fair.
The base word of "unfairness" is "fair." The prefix "un-" indicates the opposite, while the suffix "-ness" turns the adjective "fair" into a noun, referring to the quality of being unfair. Thus, "unfairness" refers to the state or condition of not being fair.
A fair die (fair dice) is a dice which isn't altered in any way, this means it has the same chance of landing on any of one of the faces. The opposite to this is a loaded dice or cheat dice. These dice have been altered in some way, maybe by changing the weight distribution so that one of the numbers on the die/dice are more likely to be rolled.
Fair = Equitable Fair = Light colour of skin and hair Fair = A festival Fair = Peasant as in "Fair weather" Fair = Not good or bad (How are you? Fair.)
The opposite (antonym) of opposite is same.
deceitful, devious, lying, shady, underhanded
The negotiations were honest and aboveboard. They were aboveboard about anything regarding the transaction, but kept the origins a secret.
she acted in a completely open and aboveboard way.
Fair, just, honest, unprejudiced...The opposite of unfair is fair.
Fair is opposite. Foul Ball, Fair Ball.
par-dessus bord
If by fair you mean just and according to the rules then the opposite will be unfair If by fair you mean pretty or blonde the opposite would be ugly or dark-haired
Ugly
fair
The opposite of fair (just, right) would be unfair or unjust. The opposite of fair (light, as in complexion) would be dark.
lie
unfair (?)