Relating to the number four or consisting of four parts. The quaternary structure of the protein is crucial for its function.
Pertaining to the geological period following the Tertiary, marked by the emergence of humans and modern climatic conditions. The Quaternary Period has seen significant fluctuations in global temperature.
Chemistry: Containing or involving four atoms, radicals, or valences; having a central atom bonded to four substituents. Benzyltrimethylammonium chloride is a quaternary salt used as a phase-transfer catalyst.