無駄骨 むだぼね
mudaboneo oru

Godan Verb (ru)
Idiomatic Expression

1. to waste one's efforts; to work to no (useful) effect

Rare
かれは、しばしば、無駄骨 むだぼね る。
karewa shibashiba mudaboneo oru.
He often goes off on wild goose chases.