Bright French article found in South New York (5)
I believe the answer is:
sunny
'bright' is the definition.
(similar in meaning)
'french article found in south new york' is the wordplay.
'french article' becomes 'un' (indefinite article in French).
'found in' means one lot of letters goes inside another.
'south' becomes 'S' (abbreviation).
'new york' becomes 'ny'.
's'+'ny'='sny'
'un' going inside 'sny' is 'SUNNY'.
(Other definitions for sunny that I've seen before include "Cheerful; fine (weather)" , "Cheerful - cloudless" , "Genial, cheerful" , "Unclouded - cheerful" , "cheerful sound" .)