interpolate

American  

[in-tur-puh-leyt] / ɪnˈtɜr pəˌleɪt /

verb (used with object)

interpolates, present (3rd person singular) interpolated, past participle, past interpolating present participle

1. to introduce (something additional or extraneous) between other things or parts; interject; interpose; intercalate.

2. Mathematics. to insert, estimate, or find an intermediate term in (a sequence).

3. to alter (a text) by the insertion of new matter, especially deceptively or without authorization.

4. to insert (new or spurious matter) in this manner.

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verb (used without object)

interpolates, present (3rd person singular) interpolated, past participle, past interpolating present participle

1. to make an interpolation.

interpolate British  

/ ɪnˈtɜːpəˌleɪt /

verb

1. to insert or introduce (a comment, passage, etc) into (a conversation, text, etc)

2. to falsify or alter (a text, manuscript, etc) by the later addition of (material, esp spurious or valueless passages)

3. (intr) to make additions, interruptions, or insertions

4. maths to estimate (a value of a function) between the values already known or determined Compare extrapolate

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Other Word Forms

Derived Forms

• noninterpolative
  adjective
• interpolatory
  adjective
• noninterpolating
  adjective
• interpolative
  adjective
• interpolable
  adjective
• interpolater
  noun
• uninterpolative
  adjective
• interpolatively
  adverb
• interpolator
  noun
• uninterpolated
  adjective

Conjugated Forms

Present

• have interpolated
  perfect
• has interpolated
  perfect 3rd person singular
• has been interpolating
  perfect progressive 3rd person singular
• are interpolating
  progressive
• have been interpolating
  perfect progressive
• interpolating
  participle
• is interpolating
  progressive 3rd person singular
• am interpolating
  progressive 1st person singular
• interpolates
  singular 3rd person

Past

• had interpolated
  perfect
• were interpolating
  progressive plural
• had been interpolating
  perfect progressive
• was interpolating
  progressive singular
• interpolated
  simple
• interpolated
  participle

Future

• will interpolate
  simple
• will have interpolated
  perfect
• will be interpolating
  progressive
• will have been interpolating
  perfect progressive

Etymology

Origin of interpolate

First recorded in 1605–15; from Latin interpolātus, past participle of interpolāre “to make new, refurbish, touch up,” equivalent to inter- “between, among, together” + -polā- verb stem (akin to polīre “to polish”) + -tus past participle suffix; see inter-, polish

Explanation

When you interpolate words into a text, you alter the text by adding words in. If you’re describing your favorite novelist's work, you might interpolate a few examples of her writing into your description. If you constantly interpolate your own snide comments into your sister's play-by-play account of an important basketball game, don't be surprised if she asks you to knock it off. In math, to interpolate means to estimate the value of something given certain data. If you’re looking at a chart that gives the level of pollutants in a lake on January 1st and February 1st, you must interpolate the level for January 15th.

Example Sentences

To get around that issue, the BEA said that it will average September and November numbers to interpolate the October missing data.

From The Wall Street Journal • Jan. 7, 2026

Is there a song in your mind that’s too sacred to sample or interpolate?

From Los Angeles Times • Sep. 18, 2025

A NeRF encodes the geometry of a scene into the weights of a neural network, which gives the model a strong ability to interpolate, or estimate, novel views of a scene.

From Science Daily • Jun. 18, 2024

As Swain explained, “we don’t have thermometers covering every square inch of the Earth,” so scientific groups use computer models to interpolate between data points, generating what is called a reanalysis.

From Scientific American • Jul. 11, 2023

Literary forgeries have been introduced into bibliography; dates have been altered; fictitious titles affixed; and books have been reprinted, either to leave out or to interpolate whole passages!

From Curiosities of Literature, Vol. 3 by Disraeli, Isaac