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)


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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 The country needs a thorough, nonpartisan investigation to connect the campaign to delegitimize the 2020 election to the violence that unfolded on January 6. Julian Zelizer, CNN, 18 Sep. 2021 The boards that supervise the buildings should take the initiative and conduct a thorough inspection at least every 10 years, and more often is better, said Yaniv Levi, president of Coast to Coast General Contractors in Hollywood, Fla. Dallas News, 5 July 2021 Even in Madoff's case, the SEC likely would have found the problems if staff had done a thorough inspection, Fanto noted. Marcy Gordon, Star Tribune, 14 Apr. 2021 Bags used for medically necessary items will be subjected to a thorough inspection at the entry screening site. Robert Higgs, cleveland, 25 Mar. 2021 Before completing any services, a Terminix technician will come to your home to perform a thorough inspection and build a plan and estimate for you. Better Homes & Gardens, 22 Mar. 2021 The superintendent said the district conducted a thorough investigation in just a few days and found enough evidence that Gipe had violated the school’s code of conduct to warrant his firing. Michael Ruiz, Fox News, 3 Sep. 2021 Here's a thorough examination of those myths and some some cold, hard facts to replace them. Alex Leanse, Popular Mechanics, 11 Aug. 2021 Under pressure from the Senate to do more, the county also hired two independent firms to conduct a thorough examination of the voting machines. Ronald J. Hansen, The Arizona Republic, 10 Aug. 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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Last Updated

21 Sep 2021

Cite this Entry

“Thorough.” Dictionary, Merriam-Webster, Accessed 22 Sep. 2021.

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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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