noun
Refers to the quality or state of being abnormal, often used in medical, psychological, or technical contexts.
この検査で異常性が認められた。
Abnormality was detected in this test.
彼の行動には異常性が感じられる。
There is a sense of abnormality in his behavior.
Compound of 異常 (abnormal) + 性 (nature, property). The exact historical derivation is uncertain, but the word follows a common pattern for forming abstract nouns.