disagreement

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

combat, contention, strife, struggle

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

clash, run-in, skirmish, tangle, tussle

feud, vendetta

attack, contention, dissension (also dissention)

debate, difference, disputation

fuss, objection, protest, protestation

fisticuffs, fracas, fray, free-for-all, melee (also mêlée)

catfight

deviance, divergence

differentiability, discriminability, distinguishability

change, modification, variation

variability, variance

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