Reason to monopolise light in film
I believe the answer is:
ground-hog day
'film' is the definition.
Both the definition and answer are singular nouns.
Perhaps there's a link between them I don't understand?
'reason to monopolise light' is the wordplay.
'reason' becomes 'ground' ('ground' can be a synonym of 'reason'**).
'to monopolise' becomes 'hog' (I've seen this before).
'light' becomes 'day' (I've seen this in other clues).
'ground'+'hog'+'day'='GROUND-HOG DAY'
'in' acts as a link.
Can you help me to learn more?
(Other definitions for ground-hog day that I've seen before include "2 February in the US -- deja vu situation -- 1993 film" , "Situation in which events are continually repeated" , "2nd February in US/Canada" , "February 2 in the US (when things repeat themselves?)" .)