Etymologically

Etymology and origin of the Latin word lac

Confidence
Established
Formation
Inherited
First attested
c. 250–184 BC, Plautus
Inherited from
Proto-Italic *glagt-
Ultimate origin
Proto-Indo-European (*glg-t-)

Pronunciation

  • Classical: [ˈɫak][1]
  • Ecclesiastical: [ˈlak][1]

Forms

lac n (genitive lactis); third declension[1] The nominative and accusative is also lacte, in Ennius, Plautus and Cato, and lact in Varro and Pliny.[2][3][4] Apuleius has a masculine accusative lactem.[4]

Etymology

It is inherited from Proto-Italic *glagt- (“milk”), inherited from Proto-Indo-European *glg-t- (“milk”).[3][1] Cognate with Ancient Greek γάλα (gála, “milk”), genitive γάλακτος (gálaktos), and Old Armenian կաթն (katʿn, “milk”).[3][2] De Vaan explains the Latin loss of the initial ⟨g-⟩ by dissimilation, and rejects both Leumann's view that the word was borrowed from Greek and Sihler's reconstruction with an initial ⟨*dl-⟩.[3]

Earliest recorded meaning

De Vaan gives Plautus as its first author;[3] in the Truculentus the nurse needs milk (lact), and Ennius has the cheek that blushed “like milk mixed with purple”.[2]

Semantic evolution

It is milk, and a type of whiteness, as in Ennius.[2][1] It was proverbial for likeness: in Plautus no water is more like water nor milk more like milk than one twin is like the other.[2] By likeness it is the milky juice of plants, as Varro's milk of the fig branch, and the spawn of oysters (Pliny the Elder).[2]

Church Latin glosses it “milk”.[5] English lactic (1790) comes through French from its genitive ⟨lactis⟩.[6]

Timeline

  • c. 250–184 BC – Plautus of a nurse's milk and of twins as like as milk.[2][3][7]
  • 204–169 BC – Ennius of milk-white skin.[2][7]
  • 116–27 BC – Varro of the milky juice of the fig.[2][7]
  • 23/24–79 AD – Pliny the Elder of oyster spawn.[2][7]
  • 1790 – English lactic.[6]

Meanings

Noun

  1. Milk, (poetic) milk-white colour.[2][1][4]
  2. The milky juice of plants.[2][1]
  3. The spawn (of oysters).[2]

Word family

  • collactāneus
  • lactāneus
  • lactāris
  • lactārius
  • lactātum
  • lacteō
  • lacteolus
  • lactēscō
  • lacteus
  • lacticīnium
  • lactifer
  • lactineus
  • dēlicus
  • lactō
  • English lactic

Usage notes

Tam similis quam lacte lactī, “as like as milk to milk”, was the Latin for “as like as two peas”.[2]

References

  1. ^ a b c d e f g Wiktionary, the free dictionary, https://en.wiktionary.org
  2. ^ a b c d e f g h i j k l m n Glare, P. G. W., ed. (2012), Oxford Latin Dictionary, 2nd ed., Oxford: Oxford University Press
  3. ^ a b c d e f de Vaan, Michiel (2008), Etymological Dictionary of Latin and the other Italic Languages, Leiden Indo-European Etymological Dictionary Series 7, Leiden; Boston: Brill
  4. ^ a b c Lewis, Charlton T.; Short, Charles (1879), A Latin Dictionary, Oxford: Clarendon Press
  5. ^ Stelten, Leo F. (1995), Dictionary of Ecclesiastical Latin, Peabody, Mass.: Hendrickson
  6. ^ a b Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
  7. ^ a b c d Köbler, Gerhard (2010), Lateinisches Abkunfts- und Wirkungswörterbuch für Altertum und Mittelalter, online ed., koeblergerhard.de

Related etymologies

  • opus · also from Proto-Indo-European
  • albus · also from Proto-Indo-European
  • potis · also from Proto-Indo-European
  • salvus · also from Proto-Indo-European
  • socius · also from Proto-Indo-European
  • signum · also from Proto-Indo-European
  • frater · also from Proto-Indo-European
  • foedus · also from Proto-Indo-European
Cite this entry

“Lac.” Etymologically, 19 Oct. 2026, etymologically.com/la/lac. Accessed 19 Oct. 2026.

Last edited on . ·