anomaly; abnormality; irregularity
Refers to something that deviates from the normal or expected state. Often used in formal or technical contexts.
This data contains anomalous values.
His behavior is abnormal.
Compound of 不 (fu, 'not') + 正常 (seijō, 'normal'). The exact historical derivation is uncertain, but the word follows a common Sino-Japanese pattern for negation.