Yeah well I say you don't get to define it for me. You can for yourself of course, but you can't by secular decree charge the word for everyone else that doesn't share your specific religious perspective, or your personal imperatives.
When you are in your church, only call it marriage if it's only between opposite sex partners. Refuse to sanctify same sex unions. Refuse to perform them. Knock yourself out. Debate how it may be used within the walls of your church all you want, restrict it there all you want, but trying to charge the word with your particular view of what it means ... imposing your definition through secular fiat and not through common usage, looks to me to be a less than satisfactory solution. It looks to me like an abridgment of the separation provided by the Establishment Clause.