fairness has 9 distinct synonyms spread across 4 of its 4 senses. Each sense below keeps its own list, because a synonym belongs to a meaning and not to a word: swapping one sense's substitute into another sense's sentence is how a thesaurus makes writing worse. Its one recorded opposite is unfairness.
Counts are distinct word forms across every sense. A synonym that appears under three senses is counted once here and shown three times below, under each sense it belongs to.
conformity with rules or standards
“the judge recognized the fairness of my claim”
ability to make judgments free from discrimination or dishonesty
the property of having a naturally light complexion
the quality of being good looking and attractive
Synonyms, antonyms and the broader and narrower relations for fairness come from Princeton University’s WordNet. Full sources and licences.