The kanji 効 generally conveys the meaning of "effect," "efficacy," "effectiveness," or "result." It implies something that produces a desired outcome or impact. This kanji is often associated with the ability to achieve a goal or create a change.

・On-yomi (音読み): コウ (kō) ・Kun-yomi (訓読み): き（く） (ki(ku))

⚫︎ 効果 Translation: Effect; effectiveness; result ⚫︎ 効く Translation: To be effective; to work; to take effect ⚫︎ 有効 Translation: Valid; effective; legitimate

The kanji 効 is a phono-semantic compound (形声文字). The left side is a component from 力 (chikara), meaning "power" or "strength". The right side is 爻 (kō), which signifies "to cross" or "interact". Therefore, 効 suggests the interaction of power, leading to a result or effect. The original meaning evolved to represent "effect" or "efficacy" through the combination of strength and interaction.