Each favoured supporter embraces United constantly (11)
I believe the answer is:
perpetually
'constantly' is the definition.
(I know that constantly can be written as perpetually)
'each favoured supporter embraces united' is the wordplay.
'each' becomes 'per' ('per' can mean for each).
'favoured' becomes 'pet' (as in a pet project).
'supporter' becomes 'ally' (an ally is a friend or supporter).
'embraces' indicates putting letters inside.
'united' becomes 'U' (abbreviation).
'pet'+'ally'='petally'
'petally' placed around 'u' is 'petually'.
'per'+'petually'='PERPETUALLY'
(Another definition for perpetually that I've seen is " ceaselessly".)