lumen

1. 1.

   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

   Synonymslm

   Broaderluminous flux unit
2. 2.

   a cavity or passage in a tubular organ

   “the lumen of the intestine”

   Broadercavity

Other forms of lumen

plural

lumina

Forms marked · are formed by the regular rule rather than recorded in the source data. English keeps a few hundred irregulars and the rest follow the pattern, so the rule is right far more often than not — but it is a rule, and the mark says so.

Questions about lumen

What does lumen mean?

lumen means "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". That is the primary sense; the word has 2 in total, listed in full on this page.

How many syllables are in lumen?

lumen has 2 syllables: lu-men. The stress falls on "lu". In IPA it is /ˈlumən/.

What is another word for lumen?

Close synonyms include lm. Each sense on this page lists its own synonyms, because a word with several meanings rarely has one substitute that works for all of them.

Is lumen a common word?

lumen is banded "Uncommon" — turns up in careful writing rather than conversation. The band comes from how often the word appears in a large corpus of everyday English, not from an editor's impression.