税
ぜい · zei · JLPT N3 · noun
tax
🌾💰 税 = 禾 grain + 兑 exchange: grain handed over to the state
Taxes were once paid in harvested rice, so the grain radical 禾 sits on the left. The reading ぜい (zei) appears in 税金 ぜいきん (tax money) and 消費税 しょうひぜい (consumption tax).
税 — grain radical 禾 + 兑 (exchange/phonetic)
税 combines 禾 (grain) with 兑 (exchange), which also hints at the sound. In ancient China taxes were paid in grain, so the character originally meant a levy of harvest given to the state. Its meaning later broadened to taxes and duties of any kind.