Interpolation
INTERPOLA'TION, noun The act of foisting a word or passage into a manuscript or book.
1. 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.
2. 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.