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

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.
Recent Examples on the Web: Adjective Hands-on testing starts with a thorough review of technical and performance data points, covering such factors as cutting swaths, noise, and battery run times where applicable. Rachel Rothman, Good Housekeeping, 29 Apr. 2022 The base management fee is the beginning, not the end of a thorough review. Kelly G. Richardson, San Diego Union-Tribune, 23 Apr. 2022 Yet the ultimate effect on taxpayers remains unclear, as the government in its haste has not produced a thorough review of the financial impact. Ryan Faughnder, Los Angeles Times, 20 Apr. 2022 Council has made individual changes to the charter over the years without a thorough review of the charter. cleveland, 14 Apr. 2022 Gina Maiola, communications director for Ivey, said this afternoon the bill would undergo the thorough review every bill receives. Mike Cason |, al, 7 Apr. 2022 The plan will undergo a thorough environmental review over the next eighteen to twenty-four months. The Salt Lake Tribune, 25 Mar. 2022 Then, after the Justice Department ordered a more thorough review, the FBI claimed its records were exempt from public disclosure. CBS News, 21 Mar. 2022 The Supreme Court on Tuesday declined to hear a dispute between the company that operates the Dakota Access oil pipeline and several Native American tribes who say the project requires a more thorough environmental review. John Fritze, USA TODAY, 22 Feb. 2022 See More

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.

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 May 2022

Cite this Entry

“Thorough.” Dictionary, Merriam-Webster, Accessed 18 May. 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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