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clumsy; awkward; unskillful
incompetent; inept; bungling; (socially) awkward; gawky; gauche
「無器用」 has another reading with different meanings.
彼は不器用だが一生懸命だ。
He's clumsy, but works hard.
不器用な指でも、慣れれば上手に縫えるようになる。
Even with clumsy fingers, you can learn to sew well with practice.
不器用だからこそ努力を惜しまない。
Because he's unskillful, he never spares effort.