interpolate
Cross references: 1. introduce in.ter.po.late \in-'t*r-p*-.la-t\ \(.)in-.t*r-p*-'la--sh*n\ \in-'t*r-p*-.la-t-iv\ \-.la-t-*r\ vb [L interpolatus, pp. of interpolare to refurbish, alter, interpolat]e, fr. inter- + -polare (fr. polire to polish) 1a: to alter or corrupt (as a text) by inserting new or foreign matter 1b: to insert (words) into a text or into a conversation 2: to insert between other things or parts : INTERCALATE 3: to estimate values of (a function) between two known values : to make insertions - in.ter.po.la.tion n
Webster's English Dictionary