Definition of thorough in English:

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Pronunciation: /ˈTHərō/


1Complete with regard to every detail; not superficial or partial: planners need a thorough understanding of the subject
More example sentences
  • Success in this environment requires a thorough understanding of systems theory.
  • Prevention only works when you have a thorough understanding about how and why things fail.
  • Whenever he was doing something in mathematics, he always strove to achieve a thorough understanding of the subject.
rigorous, in-depth, exhaustive, thoroughgoing, minute, detailed, close, meticulous, methodical, careful, complete, comprehensive, full, extensive, widespread, sweeping, all-embracing, all-inclusive
1.1Performed or written with great care and completeness: officers have made a thorough examination of the wreckage
More example sentences
  • The physician also should perform a thorough physical examination of the child, looking for any unusual marks or bruises.
  • An experienced structural engineer performed a thorough examination of the school building.
  • This is the most thorough examination by divers of the wreck site since 1982.
1.2Taking pains to do something carefully and completely: the Canadian authorities are very thorough
More example sentences
  • I'm trying very hard to be careful and thorough, and to present new information and new claims as they become available.
  • As a mathematician, Dodgson was rather conservative but certainly thorough and careful.
  • Eventually we will know these things, but we must be diligent, thorough, persistent and patient.
1.3 [attributive] Absolute (used to emphasize the degree of something, typically something unwelcome or unpleasant): the child is being a thorough nuisance
More example sentences
  • It is indicative of the thorough mess Britain's farmers are in when a beef crisis tax threatens the livelihood of pork producers.
  • Mather had excellent support in the back row, with Hills making a thorough nuisance of himself, as every openside should.
  • It was a fitting tribute to a thorough gentleman, consummate professional and true Celt.
utter, downright, thoroughgoing, absolute, complete, total, out-and-out, arrant, real, perfect, sheer, unqualified, unmitigated


Old English thuruh, alteration of thurh 'through.' Original use was as an adverb and preposition, in senses of through. The adjective dates from the late 15th century, when it also had the sense 'that goes or extends through something', surviving in thoroughfare.

  • Old English thuruh was an alteration of thurhthrough’, and the two forms were both originally used for through. The adjective ‘carried out in every detail’ dates from the late 15th century, a period when it also meant ‘going or extending through something’ surviving in late Middle English thoroughfare (literally ‘a track going through’), and familiar from Shakespeare's ‘Over hill, over dale, Thorough bush, thorough briar’ in A Midsummer Night's Dream.

Words that rhyme with thorough

borough, burgh, Burra, curragh, demurrer

For editors and proofreaders

Syllabification: thor·ough

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