D defs.my
Entry 2 senses Webster, 1913

Intercalation

· In·ter·ca·la·tion · IPA
01 n. The insertion of a day, or other portion of time, in a calendar.
  1. 1.
    The insertion of a day, or other portion of time, in a calendar.(Chron.)
  2. 2.
    The insertion or introduction of anything among others, as the insertion of a phrase, line, or verse in a metrical composition;(Geol.)
    Intercalations of fresh-water species in some localities.” — Mantell.