Bright in South — linger on (6)
I believe the answer is:
starry
'bright' is the definition.
'south linger on' is the wordplay.
'south' becomes 's' (synonyms).
'linger' becomes 'tarry' (synonyms).
'on' is a charade indicator (letters next to each other).
's'+'tarry'='STARRY'
'in' acts as a link.
(Other definitions for starry that I've seen before include "'Of cloudless climes and - - skies' (Byron)" , "Shining brightly" , "It describes the sky on a cloudless night" , "Like the Milky Way" , "Like the optimist's eyes or the sky at night" .)