Not permitted or allowed; prohibited; unlawful; as, illicit trade; illicit intercourse; illicit pleasure.

contrary to accepted morality (especially sexual morality) or convention; "an illicit association with his secretary"

contrary to or forbidden by law; "an illegitimate seizure of power"; "illicit trade"; "an outlaw strike"; "unlawful measures"

Illusory Promise

A marriage which was not celebrated according to the norm of law, yet remains a marriage

A marriage which was defective, and yet still divinely ratified, and remains a marriage

Not allowed or approved of by law.