1.VerbTo introduce (something) between other things; especially to insert (possibly spurious) words into a text.
"in verse 74, the second line is clearly interpolated, probably by some unknown medieval scribe; When interpolating an explanatory gloss, please enclose it in square brackets to make clear that it is interpolated."
2.VerbTo estimate the value of a function between two tabulated points.
3.VerbDuring the course of processing some data, and in response to a directive in that data, to fetch data from a different source and process it in-line along with the original data.