1 Physics the SI unit of luminous flux, equal to the amount of light emitted per second in a unit solid angle of one steradian from a uniform source of one candela.
2 Anat. (pl. lumina) a cavity within a tube, cell, etc.
L lumen luminis a light, an opening
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, candle power, candle-foot, candle-hour, candle-meter, decimal candle, exposure meter, flux, foot-candle, intensity, international candle, lamp-hour, light, light meter, light quantum, lumen
-hour, lumeter, luminous flux, luminous intensity, luminous power, lux, photon, quantum, unit of flux, unit of light