intercalate

/in-ˈtər-kə-ˌlāt/

borrowed from Latin intercalātus, past participle of intercalāre "to insert (a day or month) into the calendar," from inter- inter-calāre "to announce, proclaim"

verb

  1. to insert (something, such as a day) in a calendar

  2. to insert or position between or among existing elements or layers

introduce insert insinuate interpolate intercalate interpose interject mean to put between or among others. introduce is a general term for bringing or placing a thing or person into a group or body already in existence. insert implies putting into a fixed or open space between or among.