thorough

1 of 3

adjective

thor·​ough ˈthər-(ˌ)ō How to pronounce thorough (audio)
 sometimes  ˈthȯr-;
ˈthə-(ˌ)rō
1
: carried through to completion : exhaustive
a thorough search
2
a
: 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
thoroughness noun

thorough

2 of 3

preposition

archaic

thorough

3 of 3

adverb

archaic

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
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Adjective
Judge Ashford did a thorough march through the standard regulatory factors. Peter J Reilly, Forbes.com, 18 May 2025 Evans' interviews famously evolve from surface-level conversation starters to in-depth, deep dives into the lives of the talent in the hot seat, which often impresses — and, at times, shocks — them that his background research is so thorough. Skyler Caruso, People.com, 17 May 2025 No medical intervention is without risk, and on the broadest level, what these officials are asking for appears to fit the essential tenets of public health: thorough testing of vaccines before they’re debuted, and careful scrutiny of each immunization’s relative pros and cons. Katherine J. Wu, The Atlantic, 17 May 2025 Not all of the 36 states that report fluoride access report fluoride concentration levels, limiting opportunities for thorough analysis. Soph Warnes, CNN Money, 15 May 2025 See All Example Sentences for thorough

Word History

Etymology

Preposition, Adjective, and Adverb

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

First Known Use

Adjective

15th century, in the meaning defined at sense 1

Preposition

before the 12th century, in the meaning defined above

Adverb

before the 12th century, in the meaning defined above

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

Browse Nearby Words

Cite this Entry

“Thorough.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/thorough. Accessed 24 May. 2025.

Kids Definition

thorough

adjective
thor·​ough
ˈthər-ō,
ˈthə-rō
1
: marked by or carried out to completion : exhaustive
a thorough search
2
: careful about detail
a thorough worker
thoroughly adverb
thoroughness noun
Etymology

Adjective

Middle English thorow "thorough," from Old English thuruh, thurh "through" — related to thrill, through see Word History at thrill

More from Merriam-Webster on thorough

Last Updated: - Updated example sentences
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