noun
child born out of wedlock; illegitimate child
Legal and social term for a child whose parents were not married at the time of birth. 'Love child' is a softer, sometimes euphemistic gloss, but the core meaning is legal illegitimacy.
婚外子に対する差別は法律で禁止されている。
Discrimination against children born out of wedlock is prohibited by law.
彼は婚外子として生まれたが、両親
He was born out of wedlock, but his parents later married.
A more formal legal term for an illegitimate child, often used in legal contexts.
Compound of 婚外 (こんがい, 'outside marriage') + 子 (し, 'child'). The term is a straightforward Sino-Japanese construction.