From Middle English thoruȝ, þoruȝ, from Old English þuruh, a byform of Old English þurh, whence comes English through.

• (RP) IPA: /ˈθʌɹə/, /ˈθʌɹəʊ/
• (America) IPA: /ˈθʌɹoʊ/
• (America, Canada) IPA: /ˈθɝoʊ/

thorough

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), Mahatma Gandhi, The Story of My Experiments with Truth, Part I, chapter xviii:

     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.

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

• (antonym(s) of “not detailed”): cursory, superficial, surface-level

• French: minutieux, soigné
• German: gründlich
• Italian: minuzioso, accurato, dettagliato
• Portuguese: minucioso, rigoroso, detalhado
• Russian: тща́тельный
• Spanish: minucioso

• French: exhaustif
• Italian: totale, completo
• Portuguese: exaustivo
• Russian: зако́нченный
• Spanish: exhaustivo

1. (obsolete) Through. [9th]
   • 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?

thorough (plural thoroughs)

1. (UK, dialect) A furrow between two ridges, to drain off the surface water.

1. (Christianity, historical) A scheme devised in 17th-century England by Thomas Wentworth, 1st Earl of Strafford to establish absolute monarchy in England, involving the appointment of Arminian clergy.