also: めかけばら
noun
illegitimate child; born to a mistress
Refers to a child born out of wedlock, specifically to a concubine or mistress. The term is now rare and may carry a historical or literary tone.
彼は妾腹の子として生まれた。
He was born as an illegitimate child of a mistress.
妾腹の出であることが、当時は大きなハンデだった。
Being of illegitimate birth was a major disadvantage at that time.
Compound of 妾 (めかけ, 'mistress, concubine') and 腹 (はら, 'belly, womb'), literally 'mistress's womb'. The reading しょうふく is the on'yomi, while めかけばら is a kun'yomi reading.