partiality

1. The state of being partial.
2. Favorable prejudice or bias.
3. A special fondness; a predilection: had a partiality for cats. See synonyms at predilection.

noun

1. Favorable or preferential bias: favor, favoritism, partialness, preference. See fair/unfair.
2. An inclination for or against that inhibits impartial judgment: bias, one-sidedness, partisanship, prejudice, prepossession, tendentiousness. See affect/ineffectiveness, like/dislike, straight/bent.
3. A liking for something: appetite, fondness, preference, relish, taste, weakness. See like/dislike.
4. An inclination to something: bent, bias, cast, disposition, leaning, penchant, predilection, predisposition, proclivity, proneness, propensity, squint, tendency, trend, turn. See approach/retreat, like/dislike.

Definition: favoritism, fondness
Antonyms: disinterest, fairness, impartiality, justice

The noun has 2 meanings:

Meaning #1: a predisposition to like something
  Synonyms: fondness, fancy

Meaning #2: an inclination to favor one group or view or opinion over alternatives
  Synonym: partisanship
  Antonym: impartiality (meaning #1)