discordance

1. The state or an instance of disagreement; discord.
2. Genetics. The presence of a given genetic trait in only one member of a pair of identical twins.

noun

A state of disagreement and disharmony: clash, conflict, confrontation, contention, difference, difficulty, disaccord, discord, dissension, dissent, dissentience, dissidence, dissonance, faction, friction, inharmony, schism, strife, variance, war, warfare. See conflict/cooperation.

The presence of a given genetic trait in only one member of a pair of identical twins.

The occurrence of a given trait in only one member of a twin pair.

The noun has 2 meanings:

Meaning #1: a harsh mixture of sounds
  Synonym: discord

Meaning #2: strife resulting from a lack of agreement
  Synonym: discord