thumb

/θʌm/

//θʌm// noun

"thumb" is a 5-letter English headword indexed on PlainSpell.

The verdict

“thumb” is a regularly-used English word, ranked #7,071 in English word frequency and used as a noun.

#7,071
frequency rank, English
5
letters
8
tracked misspellings
17
confusable pairs

According to Wiktionary data (CC BY-SA, analyzed May 6, 2026) - The shortest and thickest digit of the hand that for humans has the most mobility and can be made to oppose (moved to touch) all of the other fingers.

Visual similarity to commonly confused words

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

thumb vs tub
60% similar
thumb vs tum
60% similar
thumb vs thus
60% similar

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

Key facts for thumb
PropertyValue
Headwordthumb
LanguageEnglish
Part of speechNoun
IPA/θʌm/
Letters5
Frequency rank#7,071
Misspellings tracked8
Confusable pairs17
SourceWiktionary (kaikki.org)

Where “thumb” 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). thumb lands here:

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

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

Spelling & Dictionary Insight

The English entry for thumb is 5 letters long, classified as a noun, and transcribed in the International Phonetic Alphabet as /θʌm/. Corpus data places it at rank #7,071 in overall English word frequency, indicating it appears regularly in written and spoken text. Wiktionary records 4 distinct senses for this headword, so context determines which meaning a reader should apply.

Our generated misspelling index lists 8 likely wrong-spelling variants for thumb, with forms such as "htumb", "thhumb", and "thmub". Each of these forms differs from the correct spelling by one small edit: a doubled letter, a dropped silent letter, or a substituted vowel. It also participates in 17 confusable-pair relationships, "tub", "tum", "thus", and more, since the words sound or look close enough that writers reach for the wrong one mid-sentence.

Etymologically, the entry records: Derived from Middle English thombe, thoume, thoumbe (“thumb”), from Old English þūma (“thumb”), from Proto-West Germanic *þūmō (“thumb”), from Proto-Germanic *þūmô (“thumb”), from Proto-Indo-European *tūm- (“to grow”). Cognate with West Frisian tomme (“thum… The correct English form is thumb, spelled T-H-U-M-B.

Definition

  1. 1
    The shortest and thickest digit of the hand that for humans has the most mobility and can be made to oppose (moved to touch) all of the other fingers.
  2. 2
    The part of a slider that may be moved linearly along the slider.
  3. 3
    A thumbnail picture.
  4. 4
    A top hatch plate for covering an excavator bucket, used to keep material in the digger bucket after scooping it up, and not letting it spill out.

Etymology

Derived from Middle English thombe, thoume, thoumbe (“thumb”), from Old English þūma (“thumb”), from Proto-West Germanic *þūmō (“thumb”), from Proto-Germanic *þūmô (“thumb”), from Proto-Indo-European *tūm- (“to grow”). Cognate with West Frisian tomme (“thumb”), Dutch duim (“thumb”), Low German Duum (“thumb”), German Daumen (“thumb”), Danish and Norwegian tomme (“inch”), Norn tum (“thumb”), Swedish tumme (“thumb”), tum (“inch”), Ancient Greek τύμβος (túmbos, “burial mound”). Also compare Welsh tyfu (“to grow”), Latin tumēre (“to swell”), Lithuanian tumėti (“to thicken, clot”), Avestan 𐬀𐬨𐬏𐬙 (amūt, “strong”), Sanskrit तुम्र (túmra, “strong, thick”). The parasitic ‐b has existed since the late 13th century. Doublet of tomb.

Synonyms

pollexdigit Ifirst digitthumby

This word in other languages

Common misspellings

Also misspelled as: htumb,thhumb,thmub,thubm,thumbb,thummb,tthumb,tuhmb

Misspelling Pattern Breakdown

How far each generated variant is from the correct spelling of thumb - measured in single-character edits (insert, delete, or substitute a letter). Larger bars are easier to catch; one-edit slips are the sneakiest.

htumb2thhumb1thmub2thubm2thumbb1thummb1tthumb1tuhmb2
Edit distance from "thumb"

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.

Frequently Asked Questions

How do you spell "thumb"?
"thumb" is spelled T-H-U-M-B. The IPA pronunciation is /θʌm/.
What does "thumb" mean?
As a noun, "thumb" means: The shortest and thickest digit of the hand that for humans has the most mobility and can be made to oppose (moved to touch) all of the other fingers.
What words are commonly confused with "thumb"?
"thumb" is commonly confused with "tub", "tum", "thus". These words look or sound similar but have different meanings. PlainSpell provides detailed comparisons for each pair.
How do you pronounce "thumb"?
The IPA (International Phonetic Alphabet) transcription for "thumb" is /θʌm/. 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 "thumb"?
Derived from Middle English thombe, thoume, thoumbe (“thumb”), from Old English þūma (“thumb”), from Proto-West Germanic *þūmō (“thumb”), from Proto-Germanic *þūmô (“thumb”), from Proto-Indo-European *tūm- (“to grow”). Cognate with West Frisian to... 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.

Using “thumb”

The practical upshot for anyone who landed here from a spell-check.

  • The one correct English spelling is T-H-U-M-B - every other letter order is a misspelling in standard orthography.
  • Say it as /θʌm/ (IPA); tap the speaker on the pronunciation badge to hear it where audio exists.
  • Don't mix it up with “tub” - see the side-by-side comparison. thumb vs tub
  • Browse more English words and confusable pairs in the same reference. English words
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 FrequencyWords open word-frequency list