Emily Dickinson Lexicon

IN-TER-PO-LA'TION, n.

1. The act of foisting a word or passage into a manuscript or book.
2. A spurious word or passage inserted in the genuine writings of an author. I have changed the situation of some of the Latin verses, and made some interpolations. Cromwell to Pope.
3. In mathematics, that branch of analysis which treats of the methods by which, when a series of quantities succeeding each other, and formed all according to some determinate law, are given, others subject to the same law may be interposed between them. Ed. Encyc.