interpolate

UK: /ɪnˈtɜːpəˌleɪt/ US: /ɪnˈtɝpəˌleɪt/ ,(in tûr′pə lāt′)

Inflections of 'interpolate' (v): (⇒ conjugate)

interpolates

v 3rd person singular

interpolating

v pres p

interpolated

v past

interpolated

v past p

WordReference Random House Learner's Dictionary of American English © 2025

in•ter•po•late /ɪnˈtɜrpəˌleɪt/   v. [~ + object] , -lat•ed, -lat•ing. 

1. to introduce (something additional or extra) between other things or parts; insert;
   interject;
   interpose:
   to interpolate an unwanted comment.

in•ter•po•la•tion /ɪnˌtɜrpəˈleɪʃən/  n. [countable]

WordReference Random House Unabridged Dictionary of American English © 2025

in•ter•po•late  (in tûr′pə lāt′), v., -lat•ed, -lat•ing. 
v.t. 

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, esp. deceptively or without authorization.
4. to insert (new or spurious matter) in this manner.

v.i. 

5. to make an interpolation.

• Latin interpolātus past participle of interpolāre to make new, refurbish, touch up, equivalent. to inter- inter- + -polā- verb, verbal stem (akin to polīre to polish) + -tus past participle suffix
• 1605–15

in•ter•po•la•ble  (in tûr′pə lə bəl), adj.  in•ter′po•lat′er, in•ter′po•la′tor, n. 
in•ter•po•la•to•ry  (in tûr′pə lə tôr′ē, -tōr′ē), in•ter′po•la′tive, adj.  in•ter′po•la′tive•ly, adv. 

Collins Concise English Dictionary © HarperCollins Publishers::

interpolate / 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. (intransitive) to make additions, interruptions, or insertions
4. to estimate (a value of a function) between the values already known or determined
   Compare extrapolate1

Etymology: 17th Century: from Latin interpolāre to give a new appearance to, from inter- + polīre to polish

inˈterpoˌlater, inˈterpoˌlator noun

inˈterpolative adjective