interpolateyoudaoicibaDictYouDict[interpolate 词源字典]
interpolate: [17] The Latin ancestor of interpolate meant literally ‘polish up’. It was interpolāre, based on a verbal element -polāre that was related to polīre ‘polish’ (source of English polish). Its meaning gradually progressed metaphorically via ‘refurbish’ and ‘alter the appearance of’ to ‘falsify, particularly by the insertion of new material’ (this last presumably arising from a reassertion of the central meaning of inter-, ‘between’).

English originally took it over in the sense ‘alter, tamper with’, but before the middle of the 17th century the notion of ‘insertion, interjection’ had begun to emerge in its own right, and has gradually taken over from ‘alter’.
=> polish[interpolate etymology, interpolate origin, 英语词源]
interpolate (v.)youdaoicibaDictYouDict
1610s, "to alter or enlarge (a writing) by inserting new material," from Latin interpolatus, past participle of interpolare "alter, freshen up, polish;" of writing, "falsify," from inter- "up" (see inter-) + polare, related to polire "to smoothe, polish." Sense evolved in Latin from "refurbish," to "alter appearance of," to "falsify (especially by adding new material)." Middle English had interpolen (early 15c.) in a similar sense. Related: Interpolated; interpolating.