Sources of illumination (5)
(Other definitions for lamps that I've seen before include "Devices for giving light" , "light fittings" , "Lights" .)
(Other definitions for candles that I've seen before include "Wicked things" , "Wax cylinders" , "They illuminate" , "They're held by sconces" , "Tealights, for example" .)
'sources of illumination' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for lights that I've seen before include "Illuminations or entrails" , "Lamps" , "organs" , "Lungs of sheep, pigs etc used as food" , "Ignites or illumines" .)