interpolation

Etymology

It is borrowed from French interpolation, recorded in Cotgrave's dictionary of 1611, or directly borrowed from Latin interpolātiō,^[2][3][4] a noun of action from interpolō (“to furbish up, alter; falsify”).^[2][3][5][6] The Latin verb is formed from inter (“among, between”) and a verb related to poliō (“to polish”).^[2][3] Etymonline reports De Vaan's account that Vendryes took the verb for polishing for a word of the fullers and the verb to have meant mending a piece of cloth, and cites Watkins's root Proto-Indo-European *pel- (“to thrust, strike, drive”).^[3] Johnson (1755) also derived it from French.^[7]

Earliest recorded meaning

The action of interpolating a text, or the fact of its being interpolated: 1612, in John Selden's notes to Drayton's Poly-Olbion.^[2] Etymonline dates it to the 1610s,^[3] and Dictionary.com to 1605–15.^[8]

Semantic evolution

In Latin the verb moved from "refurbish" to "alter the appearance of" and then to "falsify", especially by adding new material.^[3] English used the noun briefly for furbishing or polishing up (1623–78) and once for an interval of time (1615),^[2][4] but the textual sense prevailed: from 1676 it also meant the inserted word or passage itself.^[2][3] Johnson (1755) defined it as something added to the original matter.^[7] In mathematics it has meant since 1763 the calculation of an intermediate value in a series from the values already known.^[2][6] From 1849 it was used generally of any insertion among other things.^[2]

Timeline

• 1612 – the interpolating of a text.^[2]
• 1615 – an interval of time (obsolete).^[2]
• 1623 – furbishing or polishing up (obsolete, to 1678).^[2][4]
• 1676 – an interpolated word or passage.^[2]
• 1763 – in mathematics, the estimation of an intermediate value from known values.^[2]
• 1849 – an insertion among other things or between members of a series.^[2]

Meanings

Noun

1. The act of inserting words or passages into a text, especially ones that are spurious or misleading, or the state of being so altered.^[6][9][2]
2. A word or passage inserted in this way: Scholars regard the final paragraph as a later interpolation.^[6][9][2]
3. (mathematics) The process of estimating values between known values of a function or series.^[6][2]
4. An insertion of something between other things.^[2][6]
5. (obsolete, 1623–1678) The action of furbishing or polishing up.^[2][4]

Word family

• noninterpolation

Related words

• interpolate
• polish

References

1. ^ a b Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f g h i j k l m n o p q r s Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ a b c d e f g Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
4. ^ a b c d Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
5. ^ Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
6. ^ a b c d e f Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
7. ^ a b Johnson, Samuel (1755), A Dictionary of the English Language, London; 4th ed. 1773; Johnson's Dictionary Online, ed. Beth Rapp Young et al.
8. ^ Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House
9. ^ a b Collins English Dictionary (2023), Glasgow: HarperCollins