骨こつ肉にく相あい食はむ

godan verb (-mu), intransitive verb

to fight among family; to have an internecine feud

Literary and idiomatic; describes bitter conflict within a family or close-knit group, often with tragic overtones. The expression is relatively rare in everyday conversation.

• 相そう続ぞく争あらそいで兄きょう弟だいが骨こつ肉にく相あい食はむことになった。

  The inheritance dispute led the brothers to fight bitterly among themselves.

• 骨こつ肉にく相あい食はむ内ない紛ふんで会かい社しゃが傾かたむいた。

  The company was ruined by an internecine internal conflict.