constitutional amendment

The process to alter a constitution. In the US it is ratification by either two-thirds of both the Senate and H.O.R., or three quarters of the state governments. In Australia, it is a proposal ratified by the Governor General and at least one house of parliament, and then approved in a referendum by a 'double majority': a national majority of voters in the States and Territories; and a majority of voters in a majority of the States.