SKIP TO CONTENT

lumen

The lumen is a unit of measurement for the brightness of light. If a light bulb is blindingly bright, it produces a lot of lumens.

The lumen is a basic unit for measuring brightness, just as the gram is a basic unit for measuring mass. A typical light bulb in your home might produce about 1000 lumens. Lumen is related to the word luminous, which means “bright” or “radiant.”

Definitions of lumen
  1. noun
    a cavity or passage in a tubular organ
    “the lumen of the intestine”
    see moresee less
    type of:
    bodily cavity, cavity, cavum
    (anatomy) a natural hollow or sinus within the body
  2. noun
    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
    synonyms: lm
    see moresee less
    type of:
    luminous flux unit
    a measure of luminous flux per unit area
Word Family
EDITOR'S CHOICE
F1 image

Express yourself in 25 languages

  • Learn immersively - no memorization required
  • Build skills for real-world conversations
  • Get immediate feedback on your pronunciation
Get started for $7.99/month