sell, betray, show off
賣 centers on exchanging something for money or advantage: selling goods, betraying trust for gain, or showing off to attract value. The meanings connect through the idea of offering something for a return.
賣 is the traditional form of 売. It combines 士 (scholar/gentleman) with 買 (buy), suggesting a transaction where a scholar or merchant sells goods. The modern simplified form 売 replaces the lower part with a simpler shape.
A scholar 士 stands behind a buying transaction 買, but here the scholar is the one selling. Picture a gentleman showing off his wares to make a sale.
For バイ, imagine a seller shouting 'Buy! Buy!' at a market: 'Buy' sounds like バイ, and the kanji means sell.