Definition of intercalate in English:



  • 1Interpolate (an intercalary period) in a calendar.

    • ‘An extra month is intercalated every three years, just before the month of Nisan.’
    • ‘To keep the lunar calendar synchronized with the solar year, an extra month was intercalated in summer as necessary, in so-called ‘embolismic’ years.’
  • 2Insert (something) between layers in a crystal lattice, geological formation, or other structure.

    • ‘These four layers are intercalated by thick silty to sandy sequences.’
    • ‘Brecciated ironstone is derived from the disruption of banded ironstone with which it is intercalated.’
    • ‘The limestones are intercalated with thin shaly interlayers.’
    • ‘Some lenticular siltstone is intercalated with fine sandstone laminae.’
    • ‘In both areas, the volcanic rocks are intercalated with sedimentary units and the onset of basin development is marked by deposition of elastic sediments.’


Early 17th century: from Latin intercalat- proclaimed as inserted in the calendar from the verb intercalare, from inter- between + calare proclaim solemnly.