clumsy; not dexterous
不器用なので、折り紙は苦手です。
I'm clumsy, so I'm not good at origami.
なんでそんなに不器用なの？
Why are you so clumsy?
兄は全く不器用なのに、彼は優秀な外科医だ。
Although my older brother is completely clumsy, he is an excellent surgeon.