There's no geological term for a "folded up mountain." It's a bit like saying "a piled-up mountain." Mountains are formed through various geological processes, and "folded" is one of the most common ways.

Here's what we mean by "folded" mountains:

* Folding: When tectonic plates collide, the immense pressure causes the layers of rock to bend and buckle. This bending is called folding.

* Folded Mountains: Mountains that are formed primarily by these folds are called folded mountains. They often have distinctive features like ridges, valleys, and anticlines (upward folds) and synclines (downward folds).

Examples of folded mountains:

* The Himalayas

* The Alps

* The Appalachian Mountains

So, while "folded up mountain" isn't a specific geological term, it's a helpful way to think about how many mountains form. It highlights the fact that the Earth's crust can be dramatically bent and deformed to create these impressive geological features.