Here's a breakdown of its meaning:

* Cosmology: The study of the universe as a whole, including its origin, evolution, large-scale structure, and fundamental laws that govern it.

* Cosmological: An adjective describing something related to cosmology.

Here are some examples of how "cosmological" is used:

* Cosmological constant: A hypothetical form of energy that permeates all of space and is thought to contribute to the accelerating expansion of the universe.

* Cosmological redshift: The stretching of light waves from distant objects as the universe expands, making them appear redder.

* Cosmological principle: The idea that the universe is homogeneous and isotropic on large scales, meaning it looks the same in all directions and at all locations.

In short, "cosmological" refers to anything related to the vast and fascinating study of the universe.