interpolate

American  

[in-tur-puh-leyt] / ɪnˈtɜr pəˌleɪt /

verb (used with object)

interpolated, interpolating

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)

interpolated, interpolating

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

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

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; 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

“Defendants did not seek or receive permission to copy or interpolate any portion of ‘When I Was Your Man’ into ‘Flowers,’” the lawsuit adds.

From Los Angeles Times • Sep. 17, 2024

This ability to interpolate also leads to highly accurate scene reconstructions when combined with multibounce lidar, Klinghoffer says.

From Science Daily • Jun. 18, 2024

“Her outstanding skill is an ability to interpolate amusing, semi-improvised commentary within songs, in a variety of musical styles, that turns them into personal testimony,” he wrote in 1987.

From New York Times • Jan. 28, 2024

"I'll interpolate the Speaker, and see if this, too, isn't a Breach of Privilege."

From Punch, or the London Charivari, Volume 93. July 30, 1887 by