Faint lights unseen during this (8)
I believe the answer is:
blackout
'faint' is the definition.
(I know that faint can be written as blackout)
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for blackout that I've seen before include "When power's gone" , "Loss of consciousness - temporary power cut" , "Extinguishing of lights (or consciousness)" , "Faint" , "Compulsory darkness during wartime, or temporary loss of memory" .)