Intercalation
# Intercalation

Intercalation may refer to:

* Intercalation (chemistry), insertion of a molecule (or ion) into layered solids such as graphite
* Intercalation (timekeeping), insertion of a leap day, week or month into some calendar years to make the calendar follow the seasons
* Intercalation (university administration), period when a student is officially given time off from studying for an academic degree
* Intercalation (geology), a special form of interbedding, where two distinct depositional environments in close spatial proximity migrate back and forth across the border zone
* Intercalary chapter, a chapter in a novel that does not further the plot. See also frame story (sometimes called intercalation).
* In biology:
   * Intercalary segment, an appendage-less segment in the segmental composition of the heads of insects and Myriapoda
   * Intercalation (biochemistry), process discovered by Leonard Lerman by which certain drugs and mutagens insert themselves between base pairs of DNA
   * Intercalated cells of the amygdala
   * Intercalated cells of the collecting duct
   * Intercalated disc of cardiac muscle
   * Intercalated duct of exocrine glands
