Noun. 1. lower mantle-the deeper part of the mantle. layer-a relatively thin sheetlike expanse or region lying over or under another. mantle-the layer of the earth between the crust and the core.1  Facebook.. lower mantle-the deeper part of the mantle. layer-a relatively thin sheetlike expanse or region lying over or under another. mantle-the layer of the earth between the crust and the core.
Constitutional amendment. A constitutional amendment refers to the modification of the constitution of a nation or state. In many jurisdictions the text of the constitution itself is altered; in others the text is not changed, but the amendments change its effect. The method of modification is typically written into the constitution itself.
When we make a change or addition to the United States Constitution, it's known as 'amending' the Constitution. Any addition is treated as extra language, added onto the end of the Constitution, and is known as a constitutional amendment. Surprisingly, we have only 27 constitutional amendments. That's because amending the Constitution is a complicated process. The Constitution's Article V lays out the process by which the Constitution may be amended. There are actually four different ways, but only one is widely used: 1  Proposal by convention of the states, with ratification by state conventions.