noun
child of the legal wife
Archaic term used in historical contexts to distinguish a child born to the legal wife from one born to a concubine. Not used in modern Japanese.
江戸時代、向かい腹の子は嫡男として扱われた。
In the Edo period, a child of the legal wife was treated as the legitimate heir.
Compound of 向かい (mukai, 'facing, opposite') and 腹 (hara, 'belly, womb'), literally 'the opposite womb', referring to the legal wife as opposed to a concubine. The exact historical derivation is uncertain.