counterfeit, false
贗 centers on something that is not genuine: a counterfeit or false item, especially one that imitates something valuable.
贗 combines 貝 (shell, money) with 鴈, which likely contributes the sound and may relate to the idea of a false goose or imitation. The character expresses something counterfeit, especially in the context of money or valuables.
A goose (鴈) made of shells (貝) is not a real goose—it's a counterfeit. Picture a fake goose statue made of cheap shells being passed off as a valuable bronze.
For ケン, imagine a con artist named Ken trying to sell you a counterfeit goose statue: Ken -> ケン, and the fake goose is 贗.