1. The act of inserting words into a document to change or clarify the meaning. • In a negative sense, interpolation can refer to putting extraneous or false words into a document to change its meaning. Cf. INTERLINEATION.
2. (often pl.) Roman law. An editorial change made by one of the compilers of the Digests and the Justinian Code. • The compilers made insertions, deletions, and juxtapositions in the texts, but made few real changes to the substantive law. — interpolate, vb. — interpolative, adj. — interpolator, n.