noun
finishing technique; decisive strike
In martial arts, a technique intended to end a match or incapacitate an opponent; often a powerful, precise blow or hold.
彼は試合の終盤で強烈な極め技を決めた。
He landed a powerful finishing technique in the closing moments of the match.
この流派では、相手の動きを止める極め技を重視している。
This school emphasizes decisive techniques that stop the opponent's movement.
決め手 is a more general term for a decisive factor or winning move, not limited to martial arts.
必殺技 implies a 'certain-kill' or signature special move, often used in fiction or exaggerated contexts, while 極め技 is a practical finishing technique in real martial arts.
Compound of 極め (kime, 'deciding' or 'finishing', from verb 極める) and 技 (waza, 'technique'). The exact historical origin is uncertain, but the term is used in traditional Japanese martial arts to describe a decisive technique.