A Word on Gay Marriage

The U.S. Census Bureau released the following on same-sex couples...
In the United States of America there are:

• 131,729 married same-sex couple households
• 514,735 unmarried same-sex couple households

Some people would say that 131,729 marriages is a pretty decent number and we should be proud of ourselves for accomplishing that. I think that it's a nice step, but we could do better.If only ~26% of gay couple households are married and only 24% of our states even allow same-sex marriage, than those don't seem like very promising numbers to me. Don't get me wrong, I am extremely happy for those married couples and hope they have long happy lives together, and I do acknowledge that marriage isn't right for some people and that some others aren't ready for that step in their relationship. I am speaking for those couples who want to get married, but have to travel a ridiculous distance in order to find some place that will even recognize their union.
 I find it some peoples' reactions to allowing gay marriage in states somewhat disgusting. I've heard what they tell people in those churches. The last time I attended church was April of 2009. Gay marriage had just being legalized in Iowa and the pastor at my chirch was infuriated. He spent an entire two weeks preaching about how homosexuality was immoral and wrong. He kept talking about how evil and sinful it was and how it would eventually destroy our race. At that point I stood up, yelled that he was wrong, threw my bible at him, and walked out of the church. I was excommunicated and and started crying as soon as I reached my house. There my have been some overreaction on both of our parts.
I guess I can understand where they are coming from. Even if you go to dictionary.com, It specifically states that marriage is between a man and a woman. (http://dictionary.reference.com/browse/marriage) It's completely not fair. I wonder. I enough states accept same-sex marriage as a custom, is it possible to change the definition of a word? Has it been done before? I know it's possible for society to develop a new connotation for a word, but what about its denotation? How much controversy would it cause? Would it be for better or worse, or even worth the trouble? I think it would. I guess this means that the LGBT community has a little bit more to work for. I know I'm willing to put forth the effort.