| n. | 1. | Unlawful sexual intercourse on the part of an unmarried person; the act of such illicit sexual intercourse between a man and a woman as does not by law amount to adultery. |
| 2. | (Script.) Adultery. |
| Noun | 1. | fornication - voluntary sexual intercourse between persons not married to each other |
| 2. | fornication - extramarital sex that willfully and maliciously interferes with marriage relations; "adultery is often cited as grounds for divorce" Synonyms: adultery, criminal conversation |