One in France with a girl (3)
I believe the answer is:
una
'girl' is the definition.
(girl's name)
'one in france with a' is the wordplay.
'one in france' becomes 'un' (French for 'one').
'with' says to put letters next to each other.
'un'+'a'='UNA'
(Other definitions for una that I've seen before include "lady" , "Girl" , "of satellite with no sides" , "She's one in Italy." , "A single Spanish" .)