lactose
/ˈlæk.toʊs/noun
lactose is spelled L-A-C-T-O-S-E: 7 letters and 2 syllables. It appears 1.3 times per million words in written English, the 24,463rd most frequent word form (wordfreq, 2021 data). As a noun, lactose means “The disaccharide sugar of milk and dairy products, C₁₂H₂₂O₁₁, a product of glucose and galactose used as a food and in medicinal compounds” (English Wiktionary, September 2026). The plural of lactose is lactoses.
How many letters and syllables are in lactose?
| Letters | 7: L-A-C-T-O-S-E |
|---|---|
| Syllables | 2 (from its American pronunciation) |
| In writing | 1.3 times per million words; the 24,463rd most frequent word form |
| Wrong spellings searched | none measured in search |
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).
How common is lactose?
Lactose appears 1.3 times per million words in written English, the 24,463rd 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 lactose?
- UK /ˈlæk.təʊs/
- UK /ˈlæk.təʊz/
- US /ˈlæk.toʊs/
Lactose has 2 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: LL-Q1860_(eng)-Vealhurl-lactose.wav, LL-Q1860_(eng)-Vealhurl-lactose2.wav, Wikimedia Commons (author and licence on each file's page).
Forms of lactose
- lactoses plural
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
What does lactose mean?
The meanings the English Wiktionary records, quoted as written there (source below).
noun
- 1
The disaccharide sugar of milk and dairy products, C₁₂H₂₂O₁₁, a product of glucose and galactose used as a food and in medicinal compounds.
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
Lactose in Spanish, French, German and Portuguese
In the sense disaccharide sugar of milk and dairy products:
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 lactose come from?
Borrowed from French lactose, from Latin lac (“milk”) + -ose (derivation of glucose). Coined by French chemist Marcelin Berthelot.
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).