광선속의 국제 단위로, 광원으로부터 방출되는 가시광선의 총량을 나타냄.
The SI unit of luminous flux, representing the total amount of visible light emitted by a source per unit of time.
예문:
"The new flashlight has a maximum output of 1000 lm."
"A standard 60-watt incandescent bulb typically emits about 800 lm."