If you interpolate a comment into a conversation or some words into a piece of writing, you put it in as an addition.
例句
Williams interpolated much spurious matter...威廉斯插入了许多伪造的素材。These odd assertions were interpolated into the manuscript some time after 1400.这些奇怪的论断是于1400年后的某个时间被加入手稿的。
英汉词典释义
v.
插入,插(话)
Many lines have been interpolated into the manuscript at a later date.不少字句是后来添写进原手稿中去的。
篡改
interpolate improperly不恰当地窜改
英英词典释义
Verb
1. estimate the value of
2. insert words into texts, often falsifying it thereby