異い父ふ兄きょう弟だい

noun

half-sibling (different father)

Refers specifically to a brother or sister who shares the same mother but has a different father. Not used for half-siblings who share the same father but have a different mother (that is 異母兄弟).

• 彼かれには異い父ふ兄きょう弟だいが二人ふたりいる。

  He has two half-siblings with a different father.