noun
remarkable ability; amazing skill
Refers to an extraordinary, almost uncanny level of skill or competence, often in a specific field. The word is somewhat literary and not an everyday term.
彼の怪腕ぶりは業界でも有名だ。
His remarkable ability is well-known even within the industry.
怪腕を振るって難題を解決した。
He exercised his amazing skill and solved the difficult problem.
手腕 is a more common word for 'ability' or 'skill', while 怪腕 emphasizes an extraordinary, almost mysterious level of skill.
Compound of 怪 (kai, 'mysterious', 'strange') and 腕 (wan, 'arm', 'skill'). The exact origin is uncertain, but it likely emerged as a literary coinage to describe exceptional talent.