tertiary

Tertiary is an adjective meaning third in order, rank, or level. It is used in various fields to indicate a status beyond primary and secondary; the term derives from Latin tertius "third."

In education, tertiary refers to post-secondary education and training, including universities, colleges, and vocational programs. Tertiary education aims to provide advanced knowledge and skills and may lead to degrees, diplomas, or certificate qualifications.

In economics, the tertiary sector denotes services rather than goods production, including retail, finance, health, education, and hospitality. The term is used to distinguish service-oriented activities from primary (extractive) and secondary (manufacturing) sectors.

In health care, tertiary care refers to highly specialized medical services provided at major hospitals or specialized centers, often after referral from primary or secondary care.

Geology and paleontology used to use "Tertiary" to designate a period from about 66 to 2.6 million years ago; it is now replaced in formal stratigraphy by Paleogene and Neogene within the Cenozoic Era, though the term remains in historical contexts.

In biology, tertiary structure refers to the three-dimensional folding of a single polypeptide chain, stabilized by interactions among amino acid side chains, essential for protein function.

In art and color theory, tertiary colors are produced by mixing a primary color with a neighboring secondary color, resulting in hues such as red-orange, yellow-green, and blue-purple.