# tertiary

/ˈtɝʃɝi/ (US) · /tˈɜːʃjəɹi/ (UK)

Source: https://englishreference.com/word/tertiary
Updated: 2026-08-15

## Senses

### 1. third in order

adjective · CEFR C1 · Formal · Academic

coming third in a list, rank, or process.

For teachers: of third rank, importance, or order in a sequence.

- The company's primary goal is profit, but its tertiary goal is community support.
- While the primary and secondary effects of the policy were immediate, the tertiary consequences only became apparent after several years.

Usage: Usually placed before the noun it modifies.

### 2. higher education

adjective · CEFR C1 · British English · Formal

relating to education at a college or university level.

For teachers: pertaining to the level of education provided by universities and vocational colleges, following primary and secondary schooling.

- Many students move to the city to begin their tertiary education.
- The government announced a significant increase in funding for the tertiary sector to encourage more students to pursue degrees in engineering.

Usage: Commonly used in the phrase 'tertiary education' in British, Australian, and New Zealand English.

### 3. chemical structure

adjective · CEFR C2 · Technical

describing a chemical where three atoms or groups have been replaced.

For teachers: describing a carbon atom bonded to three other carbon atoms, or a compound containing such an atom.

- The scientist studied the tertiary structure of the protein to see how it folded.
- Tertiary alcohols are generally more resistant to oxidation than primary or secondary alcohols due to their molecular structure.

Usage: Used specifically within organic chemistry and biochemistry.

### 4. geological period

noun · CEFR C2 · Technical

a name for the time between 65 million and 2.6 million years ago.

For teachers: a former term for the first period of the Cenozoic era, characterized by the development of mammals.

- Fossils from the Tertiary show how early mammals began to evolve.
- Although the term Tertiary is still widely used in literature, modern geologists often prefer the terms Paleogene and Neogene.

Teaching tip: Note that in modern geology, this term is being replaced by more specific era names, but it remains common in older texts.

## Examples

- She is studying for her tertiary degree.
- The government invested heavily in tertiary education to improve the workforce's skills.
- The tertiary sector of the economy, comprising services rather than manufacturing, now dominates the national GDP.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.