Nouns

(n)abnormality, abnormalcyan abnormal physical condition resulting from defective genes or developmental deficiencies
(n)abnormality, mental defectivenessretardation sufficient to fall outside the normal range of intelligence
(n)abnormality, freakishnessmarked strangeness as a consequence of being abnormal
(n)abnormality, irregularitybehavior that breaches the rule or etiquette or custom or morality