unlawfulness by virtue of not being authorized by or in accordance with law

Being born to unmarried parents. The law assumes legitimacy via a married mother's husband, whether or not this is the true father. Illegitimacy status limits inheritance rights.

"Illegitimacy" is a term that was once in common use for the status of being born to parents who were not validly married to one another. A legal term was "bastardy." That status could be changed in either direction by civil or canon law (a case of the former occurred with the Princes in the Tower).

The state of being illegitimate.