Definition of intercalary
adjective
1(of a day or a month) inserted in the calendar to harmonize it with the solar year, e.g. 29 February in leap years: eighteen months of twenty days each and five intercalary days
2(of an academic year or period) additional to the standard course and taken at a different institution: the intercalary year is taken between the second and final years
3of the nature of an insertion: elaborate intercalary notes
4 Botany (of the meristem of a plant) located between its daughter cells, especially (in a grass) at or near the base of a leaf.
