also: うでがよい
expression, i-adjective (yoi/ii class)
skilled; skillful; competent; good at something
Describes a person who is highly capable or talented in a particular skill, craft, or profession. Often used in the form 腕がいい to mean 'has good skills'.
Antonyms: 腕が悪い
彼は本当に腕がいい料理人だ。
He is a really skilled chef.
あの大工は腕がいいから、いつも仕事が絶えない。
That carpenter is so skilled that he always has work.
Antonym meaning 'unskilled' or 'poor at something'.
From 腕 (うで, 'arm', metaphorically 'skill') + が + いい ('good'). The metaphorical use of 腕 for skill is common in Japanese.