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

Example Sentences

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
The instruction manual is especially thorough, with a section that includes food cooking tips and information on how to choose bakeware for the toaster oven. Quincy Bulin, Better Homes & Gardens, 17 Apr. 2023 All three law enforcement agencies conducted a thorough investigation of the building and the surrounding area. Staff Report, Chicago Tribune, 6 Apr. 2023 Charges are pending a thorough traffic crash investigation, which is active. Garfield Hylton, Orlando Sentinel, 3 Apr. 2023 The nonprofit again sued the Forest Service in 2008, alleging its environmental analysis was inadequate, and the court ruled the Forest Service had to do a more thorough analysis by the end of 2011. oregonlive, 1 Apr. 2023 The village council called for a thorough investigation of his killing and a general strike Saturday in protest. Isabel Debre, BostonGlobe.com, 1 Apr. 2023 But a handful of individuals familiar with the situation tell Variety that a number of employees had complained to human resources about Fleiss, which led to a thorough investigation that was conducted by an outside party in the past few months. Elizabeth Wagmeister, Variety, 30 Mar. 2023 Curwood, a history professor at the University of Kentucky, offers a thorough analysis of Chisholm’s seven terms in Congress and her presidential run. Barbara Spindel, The Christian Science Monitor, 29 Mar. 2023 See More

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'thorough.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

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

Dictionary Entries Near thorough

Cite this Entry

“Thorough.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/thorough. Accessed 29 May. 2023.

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
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!