illegitim

Illegitim is an adjective meaning not legitimate or lacking official authorization; in modern English, the standard form is illegitimate, while illegitim may appear as a historical, dialectal, or stylistic variant or in non-English contexts. The term derives from Latin illegitimus, from in- "not" + legitimus "lawful."

Historically, illegitim was most often linked to birth status, describing a child born to unmarried parents and carrying social or legal implications in inheritance, succession, or social standing. Over the past century, many jurisdictions have reformed laws to reduce or remove these distinctions, and contemporary usage typically favors neutral phrasing such as non-marital, born out of wedlock, or simply non-legitimate in strictly legal texts.

Beyond family status, illegitim can describe claims, power, or processes that lack proper authorization or recognition. For example, an illegitimate claim or illegitimate authority is one regarded as illegally or improperly grounded in law or procedure. In this sense, illegitim is used as a strong critique of legitimacy.

Because of its potential to stigmatize people, contemporary language tends to prefer precise, non-pejorative terms tailored to the context. The word remains common in historical discussions and in certain legal or formal registers, but modern usage often avoids it when referring to individuals.

See also: illegitimacy, legitimate, legitimacy, nonmarital birth, illegitimate power.