tertiary

tertiary — adjective

1. relating to the third position, rank, or stage in a sequence of things — often u

1.adjectiveC1
Definition

relating to the third position, rank, or stage in a sequence of things — often used when the first two positions or levels have already been mentioned or established.

Example

The report divided the production process into primary, secondary, and tertiary stages.

tertiary stage — position in a three-level sequence

After the primary and secondary power units failed, the tertiary system kept the hospital running.

tertiary system — third backup in a safety hierarchy

Common collocations
  • tertiary stage
  • tertiary level
  • tertiary role
  • tertiary importance
  • tertiary rank
Synonyms
  • third

    everyday equivalent; 'tertiary' is more formal and used in systematic classifications

  • third-level

    hyphenated compound, less formal but more descriptive

Antonyms

Grammar Patterns

tertiary + noun

Usage Note

Attributive only — used before a noun, not after a linking verb. Commonly pairs with primary and secondary to describe a three-part ranking or hierarchy.

Common Mistakes

His priority is tertiary to his family.
His family is a tertiary priority for him.
'tertiary' is not used with 'to' in this comparative way; it modifies a noun directly.
The issue is tertiary important.
The issue is of tertiary importance.
'tertiary' is an adjective, not an adverb.

2. relating to education that takes place after secondary school, especially at col

2.adjectiveB2
Definition

relating to education that takes place after secondary school, especially at colleges, universities, and other institutions that offer degrees and diplomas.

Example

After finishing high school, Gabriel enrolled in a tertiary institution to study engineering.

tertiary institution — college or university

The government plans to increase funding for tertiary education to make university more affordable.

tertiary education — formal term for university-level study

Common collocations
  • tertiary education
  • tertiary institution
  • tertiary student
  • tertiary study
  • tertiary qualification
  • tertiary college
Synonyms
  • higher education

    more common globally, especially in American English; slightly less formal

  • post-secondary

    used in official contexts, especially in Canada; broader and includes vocational training

Antonyms

Grammar Patterns

tertiary + noun (education, institution, student, study, qualification)

Usage Note

Frequently used in British English and other Commonwealth varieties. In American English, higher education or post-secondary education is more common.

Common Mistakes

I am studying at a tertiary.
I am studying at a tertiary institution.
'tertiary' is an adjective; it cannot stand alone as a noun in this sense.

3. relating to the part of a country's economy that provides services rather than p

3.adjectiveC1
Definition

relating to the part of a country's economy that provides services rather than producing goods — including businesses such as banking, tourism, education, healthcare, and retail.

Example

The country's economy shifted from farming to a tertiary model based on tourism and banking.

tertiary model — service-based economy

Jobs in the tertiary sector include teaching, nursing, and retail work.

tertiary sector — the service sector of an economy

Common collocations
  • tertiary sector
  • tertiary industry
  • tertiary economy
  • tertiary production
Synonyms
Antonyms
  • primary

    relating to agriculture, mining, and raw materials

  • secondary

    relating to manufacturing and construction

Grammar Patterns

tertiary + noun (sector, industry, economy)

Usage Note

Usually paired with primary (agriculture, mining) and secondary (manufacturing) to form the three-sector model of the economy.

Common Mistakes

She works in tertiary.
She works in the tertiary sector.
'tertiary' is an adjective and needs a noun like 'sector' or 'industry'.

tertiary — noun

Word family

  • tertiarily
    adverbC2
  • tertiaries
    nounC2

Synonym discussion

Sense: adjective/1

Tertiary, third, and third-level all refer to a position after the second, but they differ in register and usage. Third is the everyday word: it works in any context ('the third attempt', 'third place'). Tertiary is more formal and typically appears in systematic classifications — academic, medical, or economic hierarchies — often in the fixed sequence primary, secondary, tertiary. Third-level is a descriptive compound used in organisational contexts ('third-level support', 'third-level qualification') but is less common than tertiary in formal writing. Choose third for general conversation, tertiary for technical or academic contexts where a three-part system is named, and third-level when describing a hierarchy of service tiers.

tertiary ↗third ↗third-level

Common collocations

Nouns

Phrases

  • tertiary education
  • tertiary sector
  • tertiary industry
  • tertiary care
  • tertiary institution
  • Tertiary period

Adjectives

Etymology

LatinEnglish

Tertiary comes from the Latin word tertiarius, meaning 'of the third part or rank', which is built on tertius ('third'). Tertius itself comes from ter ('three times'). The word entered English in the mid-1500s, first used in religious contexts to describe members of a monastic third order. By the 1700s it was used in geology for the third major division of the Earth's history, and in the 1800s it spread to general and academic use for anything occupying the third position in a series.