quaternary
Definitions
Consisting of or relating to four parts or elements.
The most recent geological period in the Cenozoic era, spanning from 2.58 million years ago to the present.
Fourth in a series or order.
Examples
The quaternary period is the most recent geological time frame, spanning from 2.58 million years ago to the present.
In chemistry, a quaternary ammonium compound is often used as a disinfectant or surfactant.
The quaternary structure of a protein refers to the arrangement of multiple folded polypeptide chains into a single functional complex.