The terms de facto and de jure are often used to describe degrees and manner of apparent compliance with the law.
A de facto marriage is one where the spouses live together "under the color of validity" though the marriage is defective "for reasons of form."
A wife de facto is a one who marriage is voidable by decree, as distinguished from a wife de jure, who is a lawful wife.
A de facto contract is one which property has been conveyed from one party to another via a defective title.
See also De Jure.