In-tĕr'/ca-lā'tion, n.

n. [Lat. intercalatio, Fr. intercalation, Sp. intercalacion, It. intercalazione.] The insertion of any thing between others; introduction; as, (a.) (Chron.) The insertion of a day, or other portion of time, in a calendar. (b.) (Geol.) The intrusion of a bed or layer between other layers. “Intercalations of fresh-water species in some localities.” Mantell.