Standard Lemma guide

lumen

noun · 6 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.

  • Received-Pronunciation: /ˈluːmən/
  • General-American: lo͞oʹmən
  • General-American: /ˈlumən/
  • UK: Recorded audio is listed in the source snapshot.
  • rhymes with -uːmən
  • CMU ARPABET: L UW1 M AH0 N Digits mark lexical stress: 1 primary, 2 secondary, 0 unstressed.

1

noun

Meaning 1

In the International System of Units, the derived unit of luminous flux; the light that is emitted in a solid angle of one steradian from a source of one candela. Symbol: lm.

Definition source: English Wiktionary via Wiktextract

Topics: natural-sciences, physical-sciences, physics

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

2

noun

Meaning 2

The cavity or channel within a tube or tubular organ.

Definition source: English Wiktionary via Wiktextract

Topics: anatomy, medicine, sciences

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

3

noun

Meaning 3

The cavity bounded by a plant cell wall.

Definition source: English Wiktionary via Wiktextract

Topics: biology, botany, natural-sciences

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

4

noun

Meaning 4

The bore of a tube such as a hollow needle or catheter.

Definition source: English Wiktionary via Wiktextract

Topics: medicine, sciences

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

5

noun

Meaning 5

a cavity or passage in a tubular organ

Definition source: Princeton WordNet 3.0

Examples

  • the lumen of the intestine

Meaning relationships

Synonyms: none provided

Antonyms: none provided

Broader terms: cavity, bodily cavity, cavum

6

noun

Meaning 6

a unit of luminous flux equal to the amount of light given out through a solid angle of 1 steradian by a point source of 1 candela intensity radiating uniformly in all directions

Definition source: Princeton WordNet 3.0

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: lm

Antonyms: none provided

Broader terms: luminous flux unit

History

Etymology

Borrowed from Latin lūmen (“light, an opening”). Use as a unit was first adopted by French physicist André Blondel in 1894.

Across languages

Translations

32 source translations are retained for this English entry.

  • Arabic: لُومِن (lūmin) — SI-unit for luminous flux
  • Armenian: լյումեն (lyumen) — SI-unit for luminous flux
  • Chinese Mandarin: 流明 (liúmíng) — SI-unit for luminous flux
  • Czech: lumen — SI-unit for luminous flux
  • Finnish: luumen — SI-unit for luminous flux
  • French: lumen — SI-unit for luminous flux
  • German: Lumen — SI-unit for luminous flux
  • Greek: λούμεν (loúmen) — SI-unit for luminous flux
  • Indonesian: lumen — SI-unit for luminous flux
  • Japanese: ルーメン (rūmen) — SI-unit for luminous flux
  • Korean: 루멘 (rumen) — SI-unit for luminous flux
  • Malay: lumen — SI-unit for luminous flux
  • Polish: lumen — SI-unit for luminous flux
  • Portuguese: lúmen — SI-unit for luminous flux
  • Romanian: lumen — SI-unit for luminous flux
  • Russian: лю́мен (ljúmen) — SI-unit for luminous flux
  • Swedish: lumen — SI-unit for luminous flux
  • Tagalog: lumen — SI-unit for luminous flux
  • Thai: ลูเมน (luu-men) — SI-unit for luminous flux
  • Chinese Mandarin: 內腔 /内腔 (nèiqiāng) — anatomy: cavity within tubular organ
  • Finnish: lumen — anatomy: cavity within tubular organ
  • Finnish: ontelo — anatomy: cavity within tubular organ
  • Hebrew: נהור (n'hor) — anatomy: cavity within tubular organ
  • Japanese: 内腔 (naikū) — anatomy: cavity within tubular organ
  • Korean: 내강 (naegang) — anatomy: cavity within tubular organ
  • Portuguese: lúmen — anatomy: cavity within tubular organ
  • Romanian: lumen — anatomy: cavity within tubular organ
  • Finnish: lumen — botany: cavity bounded by cell wall
  • Finnish: ontelo — botany: cavity bounded by cell wall
  • Romanian: lumen — botany: cavity bounded by cell wall
  • Russian: по́лость (pólostʹ) — botany: cavity bounded by cell wall
  • Finnish: lumen — medicine: bore of a tube
Real reading context

lumen in complete knowledge articles

Lumen Christi High School Everyday life · Challenging · 28 uses