Standard Lemma guide

lactose

noun · 2 senses · updated from the 2026-07-25 local source snapshot

Definitions and examples are grouped by meaning. Pronunciation, history, word forms, translations, descendants, synonyms, antonyms, derived terms, and related words appear whenever the source provides them.

Sound

Pronunciation

Each Play button uses your device's default local English voice, or a natural local fallback. The selected voice name appears after playback. This is synthesized speech, not a source recording.

  • UK: /ˈlæk.təʊs/
  • UK: /ˈlæk.təʊz/
  • Southern-England: Recorded audio is listed in the source snapshot.
  • Southern-England: Recorded audio is listed in the source snapshot.
  • US: /ˈlæk.toʊs/
  • CMU ARPABET: L AE1 K T OW0 S Digits mark lexical stress: 1 primary, 2 secondary, 0 unstressed.

1

noun

Meaning 1

The disaccharide sugar of milk and dairy products, C12H22O11, a product of glucose and galactose used as a food and in medicinal compounds.

Definition source: English Wiktionary via Wiktextract

Usage: countable, uncountable

Topics: biochemistry, biology, chemistry, microbiology, natural-sciences, physical-sciences

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

2

noun

Meaning 2

a sugar comprising one glucose molecule linked to a galactose molecule; occurs only in milk

Definition source: Princeton WordNet 3.0

Examples

  • cow's milk contains about 4.7% lactose

Meaning relationships

Synonyms: milk sugar

Antonyms: none provided

Broader terms: disaccharide

History

Etymology

Borrowed from French lactose, from Latin lac (“milk”) + -ose (derivation of glucose). Coined by French chemist Marcelin Berthelot.

Across languages

Translations

88 source translations are retained for this English entry.

  • Albanian: laktoza — disaccharide sugar of milk and dairy products
  • Arabic: لَاكْتُوز (lāktūz) — disaccharide sugar of milk and dairy products
  • Arabic: لاكتوز (lāktōz) — disaccharide sugar of milk and dairy products
  • Armenian: կաթնաշաքար (katʻnašakʻar) — disaccharide sugar of milk and dairy products
  • Armenian: լակտոզ (laktoz) — disaccharide sugar of milk and dairy products
  • Basque: laktosa — disaccharide sugar of milk and dairy products
  • Belarusian: лакто́за (laktóza) — disaccharide sugar of milk and dairy products
  • Bulgarian: лактоза (laktoza) — disaccharide sugar of milk and dairy products
  • Catalan: lactosa — disaccharide sugar of milk and dairy products
  • Chinese Cantonese: 乳糖 (jyu5 tong4) — disaccharide sugar of milk and dairy products
  • Chinese: 奶糖 (leng-thn̂g, ni-thn̂g, lin-thn̂g) — disaccharide sugar of milk and dairy products
  • Chinese Mandarin: 乳糖 (rǔtáng) — disaccharide sugar of milk and dairy products
  • Czech: laktóza — disaccharide sugar of milk and dairy products
  • Danish: laktose — disaccharide sugar of milk and dairy products
  • Danish: mælkesukker — disaccharide sugar of milk and dairy products
  • Dutch: lactose — disaccharide sugar of milk and dairy products
  • Dutch: melksuiker — disaccharide sugar of milk and dairy products
  • Esperanto: laktozo — disaccharide sugar of milk and dairy products
  • Esperanto: laktosukero — disaccharide sugar of milk and dairy products
  • Estonian: laktoos — disaccharide sugar of milk and dairy products
  • Estonian: piimasuhkur — disaccharide sugar of milk and dairy products
  • Faroese: mjólkarsukur — disaccharide sugar of milk and dairy products
  • Finnish: laktoosi — disaccharide sugar of milk and dairy products
  • Finnish: maitosokeri — disaccharide sugar of milk and dairy products
  • French: lactose — disaccharide sugar of milk and dairy products
  • Galician: lactosa — disaccharide sugar of milk and dairy products
  • Georgian: ლაქტოზა (lakṭoza) — disaccharide sugar of milk and dairy products
  • German: Laktose — disaccharide sugar of milk and dairy products
  • German: Lactose — disaccharide sugar of milk and dairy products
  • German: Milchzucker — disaccharide sugar of milk and dairy products
  • Greek: λακτόζη (laktózi) — disaccharide sugar of milk and dairy products
  • Hebrew: לקטוז (laktóz) — disaccharide sugar of milk and dairy products
  • Hindi: दुग्धधु (dugdhadhu) — disaccharide sugar of milk and dairy products
  • Hungarian: laktóz — disaccharide sugar of milk and dairy products
  • Hungarian: tejcukor — disaccharide sugar of milk and dairy products
  • Icelandic: laktósi — disaccharide sugar of milk and dairy products
  • Icelandic: mjólkursykur — disaccharide sugar of milk and dairy products
  • Ido: laktoso — disaccharide sugar of milk and dairy products
  • Indonesian: laktosa — disaccharide sugar of milk and dairy products
  • Irish: lachtós — disaccharide sugar of milk and dairy products
  • Italian: lattosio — disaccharide sugar of milk and dairy products
  • Japanese: 乳糖 (nyūtō) — disaccharide sugar of milk and dairy products
  • Japanese: ラクトース (rakutōsu) — disaccharide sugar of milk and dairy products
  • Khmer: ឡាក់តូស (laktouh) — disaccharide sugar of milk and dairy products
  • Korean: 락토스 (raktoseu) — disaccharide sugar of milk and dairy products
  • Korean: 유당 (yudang) — disaccharide sugar of milk and dairy products
  • Korean: 젖당 (jeotdang) — disaccharide sugar of milk and dairy products
  • Latin: lactosum — disaccharide sugar of milk and dairy products
  • Latvian: laktoze — disaccharide sugar of milk and dairy products
  • Lithuanian: laktozė — disaccharide sugar of milk and dairy products
  • Macedonian: лактоза (laktoza) — disaccharide sugar of milk and dairy products
  • Malagasy: laktôzy — disaccharide sugar of milk and dairy products
  • Malay: laktosa — disaccharide sugar of milk and dairy products
  • Māori: huka waiū — disaccharide sugar of milk and dairy products
  • Māori: reihuka — disaccharide sugar of milk and dairy products
  • Marathi: दुग्धधु (dugdhadhu) — disaccharide sugar of milk and dairy products
  • Mongolian: лактоз (laktoz) — disaccharide sugar of milk and dairy products
  • Mongolian: суун чихэр (suun čixer) — disaccharide sugar of milk and dairy products
  • Nepali: दुग्धधु (dugdhadhu) — disaccharide sugar of milk and dairy products
  • Norwegian Bokmål: laktose — disaccharide sugar of milk and dairy products
  • Norwegian Bokmål: melkesukker — disaccharide sugar of milk and dairy products
  • Norwegian Nynorsk: laktose — disaccharide sugar of milk and dairy products
  • Norwegian Nynorsk: mjølkesukker — disaccharide sugar of milk and dairy products
  • Occitan: lactòsa — disaccharide sugar of milk and dairy products
  • Persian: لاکتوز (lâktoz) — disaccharide sugar of milk and dairy products
  • Polish: laktoza — disaccharide sugar of milk and dairy products
  • Portuguese: lactose — disaccharide sugar of milk and dairy products
  • Romanian: lactoză — disaccharide sugar of milk and dairy products
  • Russian: лакто́за (laktóza) — disaccharide sugar of milk and dairy products
  • Serbo-Croatian: laktoza — disaccharide sugar of milk and dairy products
  • Serbo-Croatian: mliječni šećer — disaccharide sugar of milk and dairy products
  • Slovak: laktóza — disaccharide sugar of milk and dairy products
  • Slovene: laktoza — disaccharide sugar of milk and dairy products
  • Slovene: mlečni sladkor — disaccharide sugar of milk and dairy products
  • Spanish: lactosa — disaccharide sugar of milk and dairy products
  • Sundanese: laktosa — disaccharide sugar of milk and dairy products
  • Sundanese: gula susu — disaccharide sugar of milk and dairy products
  • Swahili: laktosi — disaccharide sugar of milk and dairy products
  • Swedish: laktos — disaccharide sugar of milk and dairy products
  • Swedish: mjölksocker — disaccharide sugar of milk and dairy products
  • Tagalog: laktosa — disaccharide sugar of milk and dairy products
  • Thai: แล็กโทส — disaccharide sugar of milk and dairy products
  • Turkish: laktoz — disaccharide sugar of milk and dairy products
  • Turkish: süt şekeri — disaccharide sugar of milk and dairy products
  • Uzbek: laktoza — disaccharide sugar of milk and dairy products
  • Vietnamese: đường sữa — disaccharide sugar of milk and dairy products
  • Vietnamese: lactoza — disaccharide sugar of milk and dairy products
  • Welsh: lactos — disaccharide sugar of milk and dairy products
Real reading context

lactose in complete knowledge articles