We don't have synonyms for marriage law yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are marriage vow.
(N) :
the body of legal specifications and requirements and other laws that regulate the initiation, continuation, and validity of marriages, an aspect of family law, that determine the validity of a marriage, and which vary considerably among countries in terms of what can and cannot be legally recognized by the state.
(N) :
the body of legal specifications and requirements and other laws that regulate the initiation, continuation, and validity of marriages, an aspect of family law, that determine the validity of a marriage, and which vary considerably among countries in terms of what can and cannot be legally recognized by the state.