To introduce (something) between other things; especially to insert (possibly spurious) words into a text.
During 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.
To estimate the value of a function between two tabulated points.
To insert something (or oneself) between other things.
To interrupt a conversation by introducing a different subject or making a comment.
To intervene in a dispute, or in a conversation.
To be inserted between parts or things; to come between.
To offer (one's help or services).