thorough
adjective
executed without negligence or omissions.
thorough
American
[thur-oh, thuhr-oh]
/ ˈθɜr oʊ, ˈθʌr oʊ /
adjective
-
executed without negligence or omissions.
a thorough search.
- Synonyms:
- total, unqualified, sheer, downright, exhaustive, in-depth
- Antonyms:
- superficial, partial
-
thorough enjoyment.
-
extremely attentive to accuracy and detail; painstaking: a thorough analysis.
a thorough worker;
a thorough analysis.
-
having full command or mastery of an art, talent, etc..
a thorough actress.
-
extending or passing through.
adverb
noun
thorough
1
British
/ ˈθʌrə /
adjective
-
carried out completely and carefully
a thorough search
-
(prenominal) utter
a thorough bore
-
painstakingly careful
my work is thorough
Thorough
2
British
/ ˈθʌrə /
noun
Other Word Forms
Etymology
Origin of thorough
First recorded before 900; Middle English (preposition and adverb); Old English thuruh, variant of thurh through
Explanation
Thorough describes something that is painstakingly complete, like a thorough search for your missing keys in which you look for them in coat pockets, under the table, in the refrigerator — in every single place you can think of. Thorough rhymes with "burrow": "THUR-oh." It looks a lot like through but remember thorough is an adjective, so you might use it to describe a thorough investigation or a thorough review. In contrast through is used most often as a preposition — you might look through every drawer, for example, in a search — or as an adverb — you might see a hole in your pocket where coins fall through.
Vocabulary lists containing thorough
"Earth and Space"
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Harry Potter and the Prisoner of Azkaban
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Everything, Everything
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Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
The PRP requires people to sit a language and history exam and more thorough documentation.
From BBC • Jun. 26, 2026
The Justice Department said it conducted a thorough investigation into the deal and decided it would likely be good for competition.
From The Wall Street Journal • Jun. 25, 2026
Matthew O’Brien acknowledged to jurors that no one had witnessed a person starting the Lachman fire and said determining the cause of the blaze required “a thorough investigation.”
From Los Angeles Times • Jun. 24, 2026
Transport Secretary Heidi Alexander said it was "too early to speculate" on the cause of the crash while vowing "a thorough investigation ... to ensure that lessons are learnt".
From Barron's • Jun. 20, 2026
No wild vandals could have been more thorough.
From "Catch-22" by Joseph Heller
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
