Synonyms for Unfair (same or very similar meaning)
WordNet sense 1 (favoring one person or side over another):
biasedWordNet sense 2 (showing favoritism):
partialWordNet sense 3 (violating accepted standards or rules):
foul, cheatingWordNet sense 4 (not fair; marked by injustice or partiality or deception):
unjustFrom the ODE community, based on WordNetadd/edit