il·le·git·i·mate /ˌi-li-'ji-tə-mət/ adj
1: not recognized by the law as offspring; specif: born out of marriage
◇ An illegitimate child is usu. 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
illegitimate n
Merriam-Webster’s Dictionary of Law. Merriam-Webster. 1996.