The general word 'marriage' is ancient. It has nothing to do with 'christians' and their strict definitions of 'marriage'.
The general word is not redefine-able in general.
Since ancient time, marriage has been implied joining of that which is opposite.
It it not defined by human conditions or actions. As a verb, it is defined of actions in nature itself.
A goose and a gander were married. The bee spread the pollen to the stigma to a marriage of unity between the cells. The poor and rich are married with distress and misunderstandings.
If we redefine 'addition' we are implying that we can replace an action of combination such to confuse a person to believe he has not added two objects.
There are variations in 'marriage,' but only with the addition of an adjective. Forced marriage, Young marriage, new marriage, re-marriage, unhappy marriage, and the popular argumented term homosexual marriage. The term marriage does not change even if men follow the works of Satan, the liar, the deceiver. All men are truly doing is trying to force the general word 'marriage' with alternative to eternal sustainable definitions..... which they believe are eternally stable. Are animately stable. No, a change to the word 'marriage' will not change the verbal nature of the general word. Marriage is a combination of opposites.....perhaps opposite living organisms.
How can we ensure that definitions are accurate and true to the conditions of reality? Check nature. How does nature define this term. Men make the CHOICE to go against nature.....women do this too. There is no need to redefine 'marriage'..... an adjective offers plenty of accuracy of the conditions of the heart at hand.
Overall... a good kjv bible is perfect for helping understand proper terms in the English language.