Luxes

4 clues
Meter-candles
Illumination units
Illumination measures
Units of illumination
Similar answers:
Aaaautoclub
Aaltosaxes
Aalu
Abaculus
Abadwaytolunch
Ablue
Abluent
Ablur
Ablush
Ablution
Absolut
Absolute
Absolutebliss
Absoluteceiling
Absolutegravity
Absolutely
Absolutelyright
Absoluteminimum
Absolutemonarch
Absolutemuscat