Definition

1. Adjective:

   • Occurring every third year: Describes an event, publication, or activity that happens once every three years.
   • Lasting for three years: Describes something with a duration of three years.

2. Noun:

   • A 300th anniversary: The date that marks exactly 300 years after a particular event.
   • The celebration of a 300th anniversary: An event or ceremony held to commemorate something that happened 300 years earlier.

Usage Examples

• Adjective:
  • The society holds a triennial conference to present major research findings.
  • The director's term of office is triennial.
• Noun:
  • The city is preparing for its triennial next year.
  • The museum's triennial featured exhibitions on its founding history.

Advanced Usage

• "Triennial review": A formal assessment or evaluation conducted every three years.
  • The department undergoes a rigorous triennial review to maintain its accreditation.
• "Triennial cycle": A recurring three-year period or pattern.
  • The budget is planned according to a triennial cycle.

Variants and Related Words

• Triennially (adverb): Happening every three years.
  • The report is published triennially.
• Biennial (adjective/noun): Occurring every two years or lasting two years; a 200th anniversary.
• Centennial (adjective/noun): Occurring every hundred years or lasting a hundred years; a 100th anniversary.

Synonyms

• Adjective (occurring every three years): Three-yearly.
• Noun (anniversary): Tercentenary, tercentennial.

Notes on Meaning

The two main adjectival meanings—"occurring every third year" and "lasting three years"—are distinct but related by the common time frame of three years. The noun form is specific to the 300-year mark and is less commonly used in everyday language than the adjective.

Adjective

1. occurring every third year or lasting 3 years

Noun

1. the 300th anniversary (or the celebration of it)