2,208. The Definition of a "Zonah"

Hilchos Issurei Biah 18:1

Our oral tradition teaches that the word “zonah” in the Torah refers to: a woman who was not born Jewish; a Jewish woman who was intimate with a man whom she is prohibited to marry, thereby violating a universal prohibition; a woman who was intimate with a chalal (the invalid offspring of priestly stock). The latter is a zonah even when she’s permitted to marry the chalal. A woman who is guilty of bestiality, even though such is a capital offense, is not a zonah and is not disqualified from marrying a kohein because she didn’t have prohibited relations with a man. Similarly, if a man is intimate with a woman when she’s a niddah, even though she performed an act that earns kareis (spiritual excision), she isn’t a zonah and isn’t disqualified from marrying a kohein because she isn’t prohibited from marrying this man.

Hilchos Issurei Biah 18:2

If a man is intimate with an unmarried woman, even if she’s promiscuous and makes herself available to everyone, then even though she’s liable to the penalty of lashes, she is not ruled a zonah and isn’t disqualified from marrying a kohein because she’s not prohibited to marry her various partners. If she’s intimate with a man who is forbidden to her by a Torah prohibition that applies to everyone, i.e., not just kohanim, or who is prohibited by a Torah obligation, then she may not marry him and is ruled a zonah. It should go without saying that the same is true if she’s intimate with one of the prohibited relations, a non-Jew or a servant.