noun
u-onbin; euphonic change to 'u'
Linguistics term for a historical sound shift where certain mora (ku, gu, hi, bi, mi) become 'u', common in Western Japanese dialects and in classical verb forms like て形.
「書いて」の「いて」は、ウ音便の結果です。
The 'ite' in 'kaite' is a result of u-onbin.
関西弁では「ありがとう」が「おおきに」になるのも
In Kansai dialect, 'arigatou' becoming 'ookini' is also a kind of u-onbin.
促音便 refers to euphonic change to a geminate consonant (っ), while ウ音便 refers to change to 'u'.
Compound of ウ (u) + 音便 (onbin, 'euphonic change'). The term describes a specific type of sound shift in Japanese historical linguistics.