thoroughness

American  

[thur-oh-ngis, thuhr-] / ˈθɜr oʊ ŋɪs, ˈθʌr- /

noun

1. the quality of being painstakingly and comprehensively executed, without errors or omissions; the act or practice of executing tasks in this way.

   My old cookbook remains unmatched in the clarity and thoroughness of its explanations.

   They were greatly impressed by the FBI's speed and thoroughness.

2. completeness or perfection.

   I had my doubts about the thoroughness of his knowledge of the subject.

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Other Word Forms

• superthoroughness noun
• unthoroughness noun

Etymology

Origin of thoroughness

thorough ( def. ) + -ness ( def. )

Explanation

When you pay careful attention to doing a task exactly right, that's thoroughness. Your thoroughness in cleaning the kitchen means that no one would ever guess you spilled brownie batter all over the floor. Thoroughness is seeing something through with meticulous care — the word's Old English root means "from end to end." The thoroughness of your research meant that you really knew what you were getting into when you adopted a puppy. A newspaper fact-checker's thoroughness means she'll get all the important details right, and printed articles won't include mistakes. And a detective's thoroughness might result in the return of your stolen laptop.

Example Sentences

It seems unlikely that such a hodgepodge could offer the thoroughness of a traditional autobiography, but “Small Town Girls” does.

From The Wall Street Journal • Apr. 17, 2026

Just last week, researchers hotly debated the thoroughness of the contamination testing at Palisades Charter High School’s campus.

From Los Angeles Times • Jan. 28, 2026

Among its competitors, NordVPN’s privacy audits stand out for their thoroughness and frequency.

From Salon • Dec. 12, 2025

Like most laypeople, you’re not in an authoritative position to judge the accuracy and thoroughness of your estate-planning documents.

From MarketWatch • Dec. 6, 2025

But it crushed me with hopelessness, for I wanted to write of the people in my environment with an equal thoroughness, and the burning example before my eyes made me feel that I never could.

From "Black Boy" by Richard Wright