This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
誮 combines 言 (speech) with 花 (flower), but its exact historical origin and original meaning are uncertain. It may have been created as a variant or for a specific use.
The left side is speech 言, and the right side is flower 花. Imagine a gentle, flowery way of speaking, but remember the actual meaning is unclear.
For カ, picture a car decorated with flowers and a speech bubble saying 'ka': car -> カ, tying the flower-speech shape to the reading.