Adulterine

Part of speech: adjective

Pronunciation: /əˈdʌltəɹaɪn/

Definitions

1. Born outside of lawful marriage ; not legally or properly authorized, especially about possession or use
2. Having parents who are not legally married to each other ; existing without official approval or rightful authority
3. Illegitimate in birth or origin ; unlawfully owned or used without formal consent

Etymology: Adulterine comes from Latin "adulterinus," meaning "not genuine" or "counterfeit," and that sense came first. The Latin word was built from "adulter," an adulterer, and was used of things made by mixing or forging: counterfeit coins, and goods or materials that had been falsified. The image is of something illegitimate passing for the real thing, which is why the same root produced the English word for a forged or spurious object before it meant anything about birth. The link to illegitimate birth comes from the same logic. A child born outside marriage was treated as an impostor within the family's lineage, so "adulterine" came to describe such children in English. The word also took on the older sense in legal and historical contexts, and it still appears in discussions of illicitly built structures, such as medieval castles erected without royal permission, which were called adulterine castles.