Same difference?

Coming back to this business of same-sex marriages (see post of 1st March), is the argument simply a matter of semantics?  As far as I am aware, civil partnerships between same-sex couples have all the legal rights and responsibilities enjoyed (if that's the word) by married couples.  So we come back to - what constitutes a marriage?  And more to the point it seems, who "owns" the word.  The Church are in there with their boots blacked, and there are plenty of Biblical quotes that support the idea that it is the union of man and woman, and equally plenty of quotes which seem to discountenance same-sex relationships.  So is that the definitive answer?  There appear to be vicars, priests and bishops who are willing to bless same-sex unions in Church, but does this make them marriages? Like I've said before, I think what we need is some other way of describing such relationships - in other words, yes, it's just a matter of semantics, and as such the arguments can go on for ever....