Chudan Tettsui Yoko Uchi is a technique in Kyokushin karate. It translates to 'Mid-Level Hammer Fist Side Strike.' This technique involves delivering a powerful strike with the hammer fist to the opponent's side at a mid-level. The term 'Chudan' refers to the middle level, 'Tettsui' indicates the hammer fist, and 'Yoko Uchi' refers to the side strike. It is effective for targeting the ribs or midsection with significant force.