amendment

An amendment is essentially a correction. It comes in many varieties, up to and including the process of altering something through either parliamentary or constitutional procedure. In the United States, the word is often used specifically of a change to the U.S. Constitution. A constitutional amendment may be proposed by Congress with a two-thirds majority vote in both the Senate and the House of Representatives or through a constitutional convention with majority votes in two-thirds of state legislatures. Once it is ratified by Congress, it must be approved by three-fourths (i.e., 38 of 50) of the states.