Question
If an unmarried Jewish woman has a child, is the child illegitimate (a MAMZER)?
Answer
A child born out of wedlock to a single Jewish woman is not usually a MAMZER. A child is not a MAMZER unless it is born as a result of a Biblically forbidden union; for the details see Mishnah Yevamos 4:13. “MAMZER” is a technical term; it’s not equivalent to “bastard”. Note that if a married Jewish woman has a child by a man other than her husband, that child IS a MAMZER, because a woman is Biblically forbidden to have more than one husband.