millimetre
noun
millimetre is spelled M-I-L-L-I-M-E-T-R-E: 10 letters and 4 syllables. It appears about once in every 3 million words in written English, the 47,073rd most frequent word form (wordfreq, 2021 data). People search “millimeter vs millimetre” about 10 times a month (Google, United States). As a noun, millimetre means “An SI/MKS unit of measure, the length of ¹⁄₁₀₀₀ of a metre. Symbol: mm” (English Wiktionary, September 2026). The plural of millimetre is millimetres or millimètres.
How many letters and syllables are in millimetre?
| Letters | 10: M-I-L-L-I-M-E-T-R-E |
|---|---|
| Syllables | 4 (from its American pronunciation) |
| In writing | about once in every 3 million words; the 47,073rd most frequent word form |
| Wrong spellings searched | none measured in search |
| Pairs people search | |
| Same letters |
Sources: letters and syllables from the English Wiktionary's hyphenation or pronunciation and the CMU Pronouncing Dictionary; written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media); Bing searches in the United States: the average month from September 2025 to August 2026 (Microsoft Advertising keyword data through DataForSEO, read September 30, 2026); rhymes and same-letter words are computed by PlainSpell from its own word list.
How common is millimetre?
Millimetre appears about once in every 3 million words in written English, the 47,073rd most frequent word form in the list.
Source: written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media).
How do you pronounce millimetre?
- US
Millimetre has 4 syllables (counted from its American pronunciation in the CMU Pronouncing Dictionary).
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract). Recordings: En-us-millimetre.ogg, Wikimedia Commons (author and licence on each file's page).
Words people confuse with millimetre
Word pairs people search, with the monthly searches for “a vs b” (G: Google, B: Bing, United States).
Also written: millimeter.
Sources: Google and Bing searches (September 2025 to August 2026, through DataForSEO); English Wiktionary (homophones, alternative spellings).
What rhymes with millimetre?
No other word on PlainSpell ends in the same sounds as millimetre.
Spelled with the same letters in another order: millimeter.
Computed by PlainSpell from the pronunciations in the English Wiktionary (dump of September 2, 2026): a rhyme shares every sound from the last stressed vowel to the end; ordered by written frequency (wordfreq 3.1).
Forms of millimetre
- millimetres plural
- millimeter US
- millimètre rare
- millimètres plural
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
What does millimetre mean?
The meanings the English Wiktionary records, quoted as written there (source below).
noun
- 1
An SI/MKS unit of measure, the length of ¹⁄₁₀₀₀ of a metre. Symbol: mm
Holonyms: centimetre < decimetre < metre < kilometre < megametre < gigametre < terametre < petametre
noun
- 1
rareRare spelling of millimetre.
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
Millimetre in Spanish, French, German and Portuguese
In the sense unit of measure:
| Language | Words |
|---|---|
| French | millimètre |
| German | Millimeter |
| Portuguese | milímetro |
| Spanish | milímetro |
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract). Translations are Wiktionary's, by sense; a linked word has its own PlainSpell page.
Where does millimetre come from?
From French millimètre, equivalent to milli- + metre.
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).