brightness level(n = noun.attribute) brightness, light, luminance, luminosity, luminousness - the quality of being luminous; emitting or reflecting light; "its luminosity is measured relative to that of our sun"
is a kind of physical property
has particulars: illuminance, illumination, incandescence, glow, luminescence

a level, abney level, air level, amplitude level, background level, biosafety level, biosafety level 1, biosafety level 2, biosafety level 3, biosafety level 4, blood-oxygenation level dependent functional magne, brightness, brightness constancy, carpenter's level, college level, dumpy level, energy level, fuel level, ground level, groundwater level, intensity level, level, level at, level best, level crossing, level head, level off, low level flight, mason's level, noise level, o level, on the level, plumb level, poverty level, pressure level, price level, radio brightness, sea level, signal level, sound pressure level, spirit level, split level, support level, surveyor's level, threshold level, water level, y level