This article considers whether the marriage power contained in the Australian Constitution could support a Commonwealth law that recognised same sex marriages. To this end and after outlining the current constitutional meaning according to the High Court, three methods used for interpreting constitutional terms (connotation/denotation, moderate originalism, non-originalism) are examined to ascertain whether they could source such a law to the marriage power. It is submitted that none can do so without betraying their own core interpretative principle or the text and structure of the Constitution. However an alternative method for interpreting [*2] constitutional terms is proffered which may be able to establish a sufficient connection between a law that recognises same sex marriages and the marriage power. It involves recognising 'marriage' as a constitutionalised legal term of art whose meaning can be informed by developments since federation in common law and statute.