Etymograph

English

lum

Lum comes from Scots lum ‘chimney’, and perhaps goes back to Proto-Indo-European *lewk- ‘bright’.

  1. Proto-Indo-Europeanc. 4500–2500 BCE*lewk-1‘bright’root named by Wiktionary · steps between not traced
  2. Cumbricmodern*lümon1‘chimney, flue’uncertain
  3. Scotsc. 1450–presentlumb1
  4. Scotsc. 1450–presentlum1‘chimney’
  5. Englishearliest quotation 1768lum1

attested reconstructed ? uncertain or disputed deepest recorded ancestor

  1. 1 Wiktionary, English lum
  2. Earliest quotation in Wiktionary’s entry: 1768, Alexander Ross, Canto I: “Now, by this time, the ſun begins to leam,…”.

Lineage

  1. Proto-Indo-Europeanc. 4500–2500 BCE*lewk-Wiktionary, English lum‘bright’root named by Wiktionary · steps between not traced
  2. Cumbricmodern*lümonWiktionary, English lum‘chimney, flue’uncertain
  3. Scotsc. 1450–presentlumbWiktionary, English lum
  4. Scotsc. 1450–presentlumWiktionary, English lum‘chimney’
  5. Englishearliest quotation 1768lumWiktionary, English lum. Earliest quotation in Wiktionary’s entry: 1768, Alexander Ross, Canto I: “Now, by this time, the ſun begins to leam,…”

The story

Borrowed from Scots lum, Early Scots lumb; further etymology uncertain, but probably from Cumbric *lümon, related to Welsh llumon (‘chimney’) (obsolete), from Proto-Celtic *loimono.uncertain The source flags this step as uncertain. Possibly at least influenced by Old French lum (‘light’), lume (‘cooking fire’) (compare French lumière (‘light; cavity or channel within a tube or tubular organ, lumen; opening’)), from Latin lūmen (‘light; light source; opening through which light can penetrate such as an air-hole or window; opening or orifice in a water-pipe or funnel’), ultimately from Proto-Indo-European *lewk- (‘bright; to see; to shine’).

Full etymology on Wiktionary

Linked words

through Proto-Indo-European *lewk- ‘bright’

light, low, link, los, ounce, lucy, lea, lunar, luna, lynx, translucent, illumination, lucid, illuminate, lux, luminous, luce, luminosity, loach, leucine, lumen, lumia, luminescent, lune, luminary, luminal, 74 more

Today it means

noun A chimney; also, the top part of a chimney.

Sources

Sources: Wiktionary, “lum”. By Wiktionary contributors, CC BY-SA 4.0, via kaikki.org (dump of Oct 3 2026); text adapted and restructured. Language periods are conventional ranges, not dates for this word. License.

Etymograph / Proto-Indo-European *lewk- / lum

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