accent, dialect
訛 centers on speech that deviates from a standard: a regional accent or dialect. The idea is a way of speaking that sounds different or 'off' to outsiders.
訛 combines 言 (speech) with 化 (change, transform), suggesting speech that has changed or transformed from the standard. This is a standard phono-semantic compound where 化 likely also contributes the sound.
Words 言 that have changed 化 from the standard way of speaking become a local accent or dialect.
For カ, imagine a car with a thick regional accent: the car's GPS speaks in dialect, and 'car' cues カ.
accent (of one's speech)
to speak with an accent; to mispronounce
one's native dialect
provincial dialect; local accent
provincial accent
mistaken account; miscommunication
corruption (of a word or expression); corrupted form
non-standard pronunciation; dialect
non-standard pronunciation
accent
corruption; bastardisation