boxing (as an art or technique)
Refers to boxing as a martial art or technical discipline, often with a traditional or formal nuance. In modern contexts, ボクシング is more common for the sport.
He studied the art of boxing when he was young.
Compound of 拳 (fist), 闘 (fight), and 術 (technique/art). The exact historical derivation is uncertain, but the spelling is conventionally associated with the meaning 'art of boxing'.