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.
His remarkable ability is well-known even within the industry.
He exercised his amazing skill and solved the difficult problem.
Standard kanji form. 怪 suggests 'mysterious' or 'extraordinary', and 腕 means 'arm/skill'.
Irregular kanji usage. 快 means 'pleasant' or 'skillful', but this spelling is non-standard and rarely used.
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.