one's native dialect; regional accent
Polite term for the dialect or accent of one's home region. Often used when someone's speech reveals their regional origin.
See also: 国訛り
His way of speaking still has traces of his native dialect.
I was embarrassed because my regional accent slipped out.
Compound of お (honorific prefix) + 国 (country, region) + 訛り (accent, dialect). The exact historical derivation is uncertain, but the word is conventionally associated with one's native regional speech.