disagreement

clash, collision, conflict, confliction, disaccord, discord, dissonance

apartness, divarication, division

combat, contention, strife, struggle

altercation, argument, bicker, falling-out, fight, kickup, misunderstanding, quarrel, set-to

clash, run-in, skirmish, tangle, tussle

logomachy

feud, vendetta

attack, contention, dissension (also dissention)

debate, difference, disputation

fuss, objection, protest, protestation

affray [chiefly British], fisticuffs, fracas, fray, free-for-all, melee (also mêlée)

catfight

deviance, divergence

differentiability, discriminability, distinguishability

change, modification, variation

conflict, discord, discordance, dissension (also dissention), dissent, dissidence, disunity, friction, strife

variability, variance

anomalousness, dichotomy, incompatibility, incongruence, incongruity, incongruousness, nonconformity

disproportion, imbalance, inequality, nonequivalence