thor·​ough | \ ˈthər-(ˌ)ō How to pronounce thorough (audio) , sometimes ˈthȯr-; ˈthə-(ˌ)rō \

Essential Meaning of thorough

1 : including every possible part or detail a thorough investigation/search a thorough [=complete] examination a thorough understanding of the rules and regulations
2 : careful about doing something in an accurate and exact way : meticulous a thorough worker The investigator will have to be thorough.
3 chiefly British : complete or absolute a thorough disgrace a thorough mess/nuisance

Full Definition of thorough

 (Entry 1 of 3)

1 : carried through to completion : exhaustive a thorough search
2a : marked by full detail a thorough description
b : careful about detail : painstaking a thorough scholar
c : complete in all respects thorough pleasure
d : having full mastery (as of an art) a thorough musician



Definition of thorough (Entry 2 of 3)




Definition of thorough (Entry 3 of 3)


Other Words from thorough


thoroughness noun

Examples of thorough in a Sentence

Adjective … one realized that it was the restaurant's thorough and even comic Frenchness that had made it so entirely New York. — Adam Gopnik, New Yorker, 22 Mar. 2004 Bruce tells me to squat down and Koani sidles up, ears flattened, tail tucked away, and gives my face a thorough licking. — Nicholas Evans, Daily Telegraph, 26 Sept. 1998 The job was uncharacteristically thorough for a Russian contract killing—three different types of bullets riddled Mikho's body. New Republic, 15 Dec. 1997 a thorough understanding of the rules and regulations The investigator will have to be thorough.
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Recent Examples on the Web: Adjective Then, after the Justice Department ordered a more thorough review, the FBI said its records were exempt from public disclosure. Fox News, 6 Jan. 2022 Then, after the Justice Department ordered a more thorough review, the FBI said its records were exempt from public disclosure. CBS News, 6 Jan. 2022 Companies looking to resolve with the Justice Department criminal violations such as bribery should prepare for a very thorough review of their prior sins, officials said Wednesday. Dylan Tokar, WSJ, 1 Dec. 2021 Any vetting of Franklin by Bohn and the USC administration would include a thorough review of Franklin’s handling of a gang rape by four Vanderbilt football players while Franklin was coach in 2013. J. Brady Mccollough Staff Writer, Los Angeles Times, 23 Nov. 2021 That is generally because most organizations underestimate the effort and don’t conduct a thorough review of all their branded assets that require updating. Jim Heininger, Forbes, 11 Nov. 2021 However, 10 days later federal health officials lifted the pause following a thorough safety review. John Fauber, Milwaukee Journal Sentinel, 5 Nov. 2021 Wikipedia’s thorough, but not comprehensive, timeline of virtual environments misses our MOO, the Icelandic dance club, and half a dozen other early virtual experiments. Ethan Zuckerman, The Atlantic, 29 Oct. 2021 Neukirch said the firm will perform a thorough review of military records and an on-site inspection of the property. Steve Sadin,, 26 Oct. 2021

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'thorough.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of thorough


15th century, in the meaning defined at sense 1


before the 12th century, in the meaning defined above


before the 12th century, in the meaning defined above

History and Etymology for thorough

Preposition, Adjective, and Adverb

Middle English thorow, from Old English thurh, thuruh, preposition & adverb

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Time Traveler for thorough

Time Traveler

The first known use of thorough was before the 12th century

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Dictionary Entries Near thorough




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Statistics for thorough

Last Updated

12 Jan 2022

Cite this Entry

“Thorough.” Dictionary, Merriam-Webster, Accessed 23 Jan. 2022.

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More Definitions for thorough


thor·​ough | \ ˈthər-ō How to pronounce thorough (audio) \

Kids Definition of thorough

1 : being such to the fullest degree : complete a thorough search
2 : careful about little things a thorough worker

Other Words from thorough

thoroughly adverb
thoroughness noun

More from Merriam-Webster on thorough

Nglish: Translation of thorough for Spanish Speakers

Britannica English: Translation of thorough for Arabic Speakers


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