illegitimate

adjective | \ ˌi-li-ˈji-tə-mət \ | il·le·git·i·mate

1. : not recognized by the law as offspring; specifically : born out of marriage : born out of marriage

   Note: An illegitimate child is usually legitimated by his or her parents' later marriage. Illegitimate children generally have the same inheritance rights under intestate successions as legitimate children; statutes limiting their inheritance rights have been found to violate the equal protection clause.

2. : not valid according to law