The definition is very important as it has to be used in various religions; as in Hindus, Muslims, Christians, Parsi, Zeus, etc. Better go with the proper Acts and from there you can know the ingredients of every type of marriage and further if you want I can write tomorrow as I am writing legal books and as per Hindu there are 18 types of marriages- which type of marriage definition you want I can dictate.
Hindu Law-Asura marriage-Test of-Difference between Asura and Brahma marriage- Presumption that every Hindu marriage is in Brahma form-Objector must prove the contrary--Effect of bridegroom bearing expenses of marriage-Kanyadan.
Marriage is the social decorum of the relationship, under which the man and women establish their decision to live as husband and wife. This relationship can be performed religiously and has the legal binding.