An Interpolation

1. (music) An abrupt change in elements, with continuation of the first idea.
2. (mathematics, sciences) The process of estimating the value of a function at a point from its values at nearby points.
3. (computing) The process of including and processing externally-fetched data in a document or program; see interpolate.
4. That which is introduced or inserted, especially something foreign or spurious.

(including and processing externally-fetched data): transclusion