Definitions

1. adjective

of or relating to four; consisting of four parts or components

“The quaternary structure of proteins is crucial to their function.”

2. noun

a fourth part or component

“The quaternary of the engine consists of the four cylinders.”

3. noun

a period of geologic time, especially the most recent period of the Cenozoic Era, characterized by the presence of humans and their activities

“The quaternary period has seen significant changes in the Earth’s climate.”

4. noun

a quadrilateral, especially in geometry

“The quaternary is a type of polygon with four sides.”