Threat of proper illumination? (5)

I believe the answer is:

peril

'threat' is the definition.
(I've seen this in another clue)

'of proper illumination?' is the wordplay.
'of' indicates a hidden word.
'PERIL' can be found hidden inside 'proper illumination'.

(Other definitions for peril that I've seen before include "Quest" , "Great danger" , "risk" , "Hazardous situation" , "Exposure to harm" .)

I've seen this clue in The Guardian.

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