*leuk-

Reconstruction

The root is *leu̯k- "to become bright" in LIV and *leuk- in de Vaan, Kroonen, Kloekhorst and Adams.^{[1][2][3][4][5]} Sihler and Ringe write *lewk-.^[6][7]

Morphology

LIV reconstructs a root aorist *léu̯k-/luk- in Hittite lukk- (“to get light, dawn”) and Vedic रुचान (rucāná-, “lit up”), a thematic present *léu̯k-e- in Sanskrit रोचते (rócate, “shines”), a perfect, and a causative-iterative *lou̯k-éi̯e- in Vedic रोचयति (rocáyati, “makes shine”).^[1] Latin lūceō (“to shine”) is an innovated essive, and the transitive Old Latin lūceō "to make shine" is the causative.^[1] Kümmel adds a possible present *luk-éi̯e- and, as an innovation, Greek λεύσσω (leússō, “I see”); since the root *leu̯t- is to be deleted, that verb must after all be attached here.^[8] Kloekhorst reconstructs the Hittite middle as *leuk-to.^[4]

Evidence

LIV's formations come from Hittite, Tocharian, Indo-Iranian, Latin, Armenian, Baltic and Slavic.^[1] Beekes says the meaning "to see" of Greek λεύσσω (leússō) arose from "to light up".^[9]

Meanings

1. to become bright,^[1] to shine^[3]

LIV's Lithuanian láukti (“to wait, expect”) belongs to an uncertain *lṓu̯k-i̯e-.^[1]

Derivatives

• The root noun in Latin lūx (“light”).^[2]
• *le/ouk-s-mn in Latin lūmen (“light”).^[2]
• *louko- in Latin lūcus (“wood, glade”), Lithuanian laũkas (“field”) and Sanskrit लोक (loká-, “free space, world”).^[10]
• Ancient Greek λευκός (leukós), a verbal noun like Sanskrit रोच (rocá-, “bright”).^[10]
• The t-stem *leuk-ot- in Proto-Germanic *leuhada- (“light”) and Hittite lukkatt- (“dawn”).^[3]
• Proto-Slavic *lučь (“ray, torch”).^[11]

Reflexes

• Anatolian: Hittite lukk- (“to get light, dawn”).^[4]
• Tocharian: Tocharian B lyuketär (“shines”), listed by LIV.^[1]
• Indo-Aryan: Sanskrit रोचते (rócate, “shines”), listed by LIV.^[1]
• Greek: Ancient Greek λευκός (leukós), Ancient Greek λεύσσω (leússō, “to see”).^[10][9]
• Italic: Latin lūx (“light”).^[2]
• Armenian: Old Armenian լոյս (loys, “light”).^[12]
• Germanic: Gothic 𐌻𐌹𐌿𐌷𐌰𐌸 (liuhaþ, “light”), Old English lēoht (“light”).^[3]
• Baltic: Lithuanian láukti (“to wait, expect”).^[13]

References

1. ^ a b c d e f g h Rix, Helmut, et al. (2001), Lexikon der indogermanischen Verben, 2nd ed., Wiesbaden: Reichert, p. s.v. *leu̯k-
2. ^ a b c d de Vaan, Michiel (2008), Etymological Dictionary of Latin and the other Italic Languages, Leiden Indo-European Etymological Dictionary Series 7, Leiden; Boston: Brill, p. s.v. lūx
3. ^ a b c d Kroonen, Guus (2013), Etymological Dictionary of Proto-Germanic, Leiden Indo-European Etymological Dictionary Series 11, Leiden / Boston: Brill, p. 333
4. ^ a b c Kloekhorst, Alwin (2008), Etymological Dictionary of the Hittite Inherited Lexicon, Leiden: Brill, p. 530
5. ^ Adams, Douglas Q. (2013), A Dictionary of Tocharian B, 2nd ed., Amsterdam: Rodopi, p. 603
6. ^ Sihler, Andrew L. (1995), New Comparative Grammar of Greek and Latin, New York: OUP
7. ^ Ringe, Don (2017), From Proto-Indo-European to Proto-Germanic, 2nd ed., Oxford: Oxford University Press
8. ^ Kümmel, Martin Joachim, Addenda und Corrigenda zu LIV², online document, last change 16 June 2026, p. 62
9. ^ a b Beekes, Robert S. P. (2010), Etymological Dictionary of Greek, with the assistance of Lucien van Beek, Leiden Indo-European Etymological Dictionary Series 10, Leiden; Boston: Brill, p. s.v. λεύσσω
10. ^ a b c Beekes, Robert S. P. (2010), Etymological Dictionary of Greek, with the assistance of Lucien van Beek, Leiden Indo-European Etymological Dictionary Series 10, Leiden; Boston: Brill, p. s.v. λευκός
11. ^ Derksen, Rick (2008), Etymological Dictionary of the Slavic Inherited Lexicon, Leiden Indo-European Etymological Dictionary Series 4, Leiden / Boston: Brill, p. 290
12. ^ Martirosyan, Hrach K. (2010), Etymological Dictionary of the Armenian Inherited Lexicon, Leiden: Brill, p. 325
13. ^ Derksen, Rick (2015), Etymological Dictionary of the Baltic Inherited Lexicon, Leiden: Brill, p. 289