The unlikely event of its being sour? (3,6)
I believe the answer is:
off chance
'sour?' is the definition.
Both the definition and answer are singular nouns.
Maybe they are linked in a way I don't understand?
'the unlikely event of its' is the wordplay.
I cannot quite see how this works, but
'event' could be 'chance' (chance event is a kind of event) and 'chance' is found within the answer.
'of' could be 'o' and 'o' is found in the answer.
This explanation may well be incorrect...
'being' acts as a link.
Can you help me to learn more?
(Other definitions for off chance that I've seen before include "Vague possibility" , "Not much likelihood" , "Just a slight possibility" , "Remote possibility" .)