accent, dialect
譌 centers on variation in speech: a regional accent or dialect that differs from the standard form.
譌 combines 言 (speech) with 爲, which likely contributes the sound and may relate to change or deviation, suggesting speech that deviates from the norm.
Words (言) that are 'off' or changed (爲 can suggest alteration) become a local accent or dialect.
For カ, imagine a car with a distinct regional accent honking: car -> カ, and its unique sound represents a dialect.
variant kanji form; unorthodox kanji form