Illumination needed for blatant hold-up? (8)
I believe the answer is:
daylight
'illumination' is the definition.
(I have seen 'Natural illumination ' mean 'daylight' so perhaps 'illumination' could also mean 'daylight')
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for daylight that I've seen before include "Practice of moving time back an hour in spring" , "Visible gap between two things; dawn" , "Naturally, it enables us to see" , "clear gap" , "Clear space" .)