1. inserted in a calendar to harmonize it with the solar year
Usage: technical; calendar terminology
2. inserted or interpolated between other things
Usage: formal

Examples

• February 29th is an intercalary day that occurs every four years.
• The intercalary month was added to keep the lunar calendar aligned with the seasons.
• Leap years contain an intercalary day to account for the extra quarter day in Earth’s orbit.
• The ancient Romans used intercalary months to adjust their calendar system.
• An intercalary chapter was inserted between the main sections of the book.
• The intercalary verse served as a bridge between the two main themes.