expression
family quarrel; feud among blood relatives
Idiomatic expression referring to a serious dispute or conflict within a family, emphasizing the bitterness of fighting one's own flesh and blood.
遺産をめぐって血肉の争いが起きた。
A family quarrel broke out over the inheritance.
あの兄弟の血肉の争いはもう何年も続いている。
That feud between the brothers has been going on for years.
Composed of 血肉 (flesh and blood) and 争い (quarrel), literally 'a quarrel of flesh and blood', figuratively a conflict among blood relatives.