thorough definition

English

Alternative forms

• thoro (informal)

Etymology

From Middle English thoruȝ, þoruȝ, from Old English þuruh, a byform of Old English þurh, whence comes English through. The adjective derives from the preposition and adverb. The word developed a syllabic form in cases where the word was fully stressed: when it was used as an adverb, adjective, or noun, and less commonly when used as a preposition.

Pronunciation

• (Received Pronunciation) IPA^(key): /ˈθʌɹə/
• (General American) IPA^(key): /ˈθʌɹoʊ/, /ˈθɜɹoʊ/

• Audio (UK)

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• Audio (US)

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  (accents without the hurry–furry merger)

• Audio (US)

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  (accents with the hurry–furry merger)
• Rhymes: -ʌɹə, -ʌɹəʊ

Adjective

thorough (comparative thorougher, superlative thoroughest)

1. Painstaking and careful not to miss or omit any detail.

   The Prime Minister announced a thorough investigation into the death of a father of two in police custody.

   He is the most thorough worker I have ever seen.

   The infested house needs a thorough cleansing before it will be inhabitable.

2. Utter; complete; absolute.
   • 1925-29, Mahadev Desai (translator), M.K. Gandhi, The Story of My Experiments with Truth, Part I, chapter xviii^[1]:

     I was elected to the Executive Committee of the Vegetarian Society, and made it a point to attend every one of its meetings, but I always felt tongue-tied. Dr. Oldfield once said to me, 'You talk to me quite all right, but why is it that you never open your lips at a committee meeting? You are a drone.' I appreciated the banter. The bees are ever busy, the drone is a thorough idler. And it was not a little curious that whilst others expressed their opinions at these meetings, I sat quite silent. Not that I never felt tempted to speak. But I was at a loss to know how to express myself. All the rest of the members appeared to me to be better informed than I. Then it often happened that just when I had mustered up courage to speak, a fresh subject would be started. This went on for a long time.

Synonyms

• (detailed): comprehensive, rigorous, scrupulous; see also Thesaurus:meticulous or Thesaurus:comprehensive
• (utter; complete; absolute): downright, outright, unmitigated; see also Thesaurus:total

Antonyms

• (not detailed): cursory, superficial, surface-level

Derived terms

• thoroughbred
• thoroughgoing
• thoroughly
• thoroughness
• thorough-stitch

Translations

Preposition

thorough

1. (obsolete) Through. [9th–19th c.]
   • 1590, Edmund Spenser, “Book II, Canto XII”, in The Faerie Queene. […], London: […] [John Wolfe] for William Ponsonbie, →OCLC:

     Ye might haue ſeene the frothy billowes fry
     Vnder the ſhip, as thorough them ſhe went […]

   • 1599 (first performance), William Shakespeare, “The Tragedie of Iulius Cæsar”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, →OCLC, [Act V, scene i], line 109:

     You are contented to be led in triumph
     Thorough the streets of Rome?

Noun

thorough (plural thoroughs)

1. (UK, dialect) A furrow between two ridges, to drain off the surface water.
   • 1733, William Ellis, Chiltern And Vale Farming Explained:

     The Ignorance and Idleness of the Plowman, who either goes so shallow, or plows his Thoroughs so wide, or misses Part of the Ground.