noun
popularly accepted on-reading of a kanji
A kanji reading widely used in Japanese but not directly derived from historical Chinese pronunciations; often arose through common usage or misreading.
「消耗」の「耗」を「もう」と読むのは慣用音の一例だ。
Reading 耗 as もう in 消耗 is one example of a popularly accepted on-reading.
音読み is the general term for Sino-Japanese readings, while 慣用音 refers specifically to those that became accepted through common use rather than direct Chinese derivation.
漢音 is a systematic layer of Sino-Japanese readings based on Tang dynasty Chinese, whereas 慣用音 are non-systematic, popularized readings.
呉音 is an older layer of Sino-Japanese readings, while 慣用音 are later, often irregular, popular readings.
Compound of 慣用 (common use) and 音 (sound, reading). The term itself is a modern linguistic classification.