thorough

/ˈθʌɹə/

//ˈθʌɹə// adj

"thorough" is a 8-letter English headword indexed on PlainSpell.

The verdict

“thorough” has 12 generated spelling variants in the English index at frequency #7,512. The variants make it a useful spelling check.

#7,512
frequency rank, English
27,828
“T” headwords
12
tracked misspellings
4
confusable pairs

According to Wiktionary data (CC BY-SA, analyzed May 6, 2026) - Painstaking and careful not to miss or omit any detail.

Corpus desk

Index EN-thorough · thorough · English

thorough · rank #7,512 · 12 variants · 4 confusables

  • FREQ-COMMON #7,512
  • LEN-LONG 8 letters
  • VOW-3 3 vowels
  • CONFUS-MID 4 pairs
  • VAR-MID 12 variants
  • BOOK-DENSE 27,828
  • PHOTO-FINISH thereafter

Nearest frequency peer: thereafter (-1 rank slots)

Read with this headword: Spelling guide for this pattern

Desk codes from Wiktionary headword shape, FrequencyWords rank tier, confusable-pair count, generated misspelling depth, letter-cohort book size, and photo-finish peer. Not a difficulty grade.

Frequency neighbourhood for “thorough”

Lower corpus rank = more everyday usage (inverted bar length for readability)

corpus weight

What this shows Bars show where “thorough” sits against the nearest ranked English headwords in the FrequencyWords band, not a reprint of letter-browse containment.

Source FrequencyWords open word-frequency list As of May 6, 2026

Visual similarity to commonly confused words

How many letter changes separate each confused pair (Levenshtein distance, normalized).

thorough vs though
75% similar
thorough vs trough
75% similar
thorough vs through
88% similar

Source: PlainSpell confusable corpus (Wiktionary, CC BY-SA).

Key facts for thorough
PropertyValue
Headwordthorough
LanguageEnglish
Part of speechAdjective
IPA/ˈθʌɹə/
Letters8
Frequency rank#7,512
Misspellings tracked12
Confusable pairs4
SourceWiktionary (kaikki.org)

Where “thorough” sits in English frequency

Every-word frequency runs from the handful of words we use constantly (left) to the long tail used once in a blue moon (right). thorough lands here:

#1#100#1K#10K#100K
← used constantlyrarely used →

Scale is logarithmic (each tick is 10× rarer). Source: FrequencyWords open word-frequency list.

A misspelling magnet

The generator records 12 spelling variants around thorough (IPA /ˈθʌɹə/), anadjective. Corpus frequency is #7,512 among 27,828 “T” headwords. Wiktionary lists 2 senses, so context still picks the gloss.

Our generated misspelling index lists 12 likely wrong-spelling variants for thorough, with forms such as "htorough", "thhorough", and "thoorugh". Every one of these variants traces to a single-character edit -- an added or dropped letter, a swapped consonant, or a vowel swap -- the kind of slip a spell-checker is built to catch. It also participates in 4 confusable-pair relationships, "though", "trough", "through", and more, since the words sound or look close enough that writers reach for the wrong one mid-sentence.

Etymologically, the entry records: 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… The correct English form is thorough, spelled T-H-O-R-O-U-G-H.

Definition

  1. 1
    Painstaking and careful not to miss or omit any detail.
  2. 2
    Utter; complete; absolute.

Recorded use

Wiktionary examples

These source excerpts show how thorough appears in context. They illustrate usage; the definition above remains the entry’s reference meaning.

  1. The Prime Minister announced a thorough investigation into the death of a father-of-two in police custody.
  2. Not enough! Your work has to be thorougher than this.

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.

Synonyms

Antonyms

This word in other languages

Common misspellings

Also misspelled as:

  • htorough
  • thhorough
  • thoorugh
  • thoroguh
  • thorouggh
  • thoroughh
  • thorouhg
  • thorrough
  • thoruogh
  • throough
  • tohrough
  • tthorough

Misspelling Pattern Breakdown

How far each generated variant is from the correct spelling of thorough - expressed in single-character edits (insert, delete, or swap one letter). Bigger bars stand out at a glance; a one-edit slip is the hardest to catch.

htorough2thhorough1thoorugh2thoroguh2thorouggh1thoroughh1thorouhg2thorrough1
Edit distance from "thorough"

Definitions, pronunciation, and etymology for this entry are drawn from Wiktionary via the kaikki.org structured extract (CC BY-SA); frequency ordering uses the FrequencyWords open word-frequency list (2018 English corpus, MIT). See the methodology for how each field is sourced and updated.

PlainSpell is rendered directly from structured Wiktionary extracts and open word-frequency lists, no number is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of May 6, 2026. Primary sources: Wiktionary (via kaikki.org) and FrequencyWords.

Frequently Asked Questions

How do you spell "thorough"?
"thorough" is spelled T-H-O-R-O-U-G-H. The IPA pronunciation is /ˈθʌɹə/.
What does "thorough" mean?
As an adjective, "thorough" means: Painstaking and careful not to miss or omit any detail.
What words are commonly confused with "thorough"?
"thorough" is commonly confused with "though", "trough", "through". These words look or sound similar but have different meanings. PlainSpell provides detailed comparisons for each pair.
How do you pronounce "thorough"?
The IPA (International Phonetic Alphabet) transcription for "thorough" is /ˈθʌɹə/. Click the speaker icon on the pronunciation badge above to hear it spoken aloud where audio is available.
What is the origin of the word "thorough"?
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 stre... See the full etymology section above for more details.
Is PlainSpell free to use?
Yes, PlainSpell is a completely free word reference. You can look up definitions, pronunciations, confusable pairs, homophones, and spelling corrections across 5 languages without any sign-up or subscription.

Similar English words by spelling shape

Same letter count and similar misspelling depth for "thorough", not the corpus desk frequency band.

Same letter count

Frequency-ranked English headwords with 8 letters (nearest by frequency rank).

Similar misspelling depth

Headwords with a similar count of attested misspellings (12 here; floor ≥5).

Data Source

Wiktionary (via kaikki.org), licensed under CC BY-SA & GFDL. Word ordering uses an open word-frequency list; misspelling variants are generated by edit-distance from the correct headword.

Source: Wiktionary (via kaikki.org) Structured Wiktionary extract

Source: FrequencyWords open word-frequency list