name of a river in Shanxi, crafty
嬀 is a rare kanji with two distinct senses: it names a specific river in Shanxi, and it can mean crafty or cunning. These meanings do not share one clear conceptual center, so treat them as separate uses.
嬀 combines 女 (woman) with 爲, which likely acts as a phonetic component. The exact historical development is uncertain, and the connection between the river name and the crafty meaning is unclear.
A woman 女 beside the complex shape 爲: imagine a crafty woman by the river named 嬀, using her wits to navigate its currents.
For キ, picture a key hidden by the crafty woman near the river: key -> キ, and she uses it to unlock a secret.