A city to be entered by a Latin couple (5)
I believe the answer is:
lille
'a city' is the definition.
(I've seen this before)
'be entered by a latin couple' is the wordplay.
'a latin couple' means two substitutions for 'latin'.
'be' becomes 'lie' (lying is a kind of being).
'entered by' is an insertion indicator (I've seen this in other clues).
'latin' becomes 'l'.
'latin' becomes 'l'.
'l'+'l'='ll'
'lie' enclosing 'll' is 'LILLE'.
'to' is the link.
(Other definitions for lille that I've seen before include "Stop before Paris" , "European city" , "Feeling unwell in the French town" , "[FRANCOPHOBIA] would prevent you appreciating it" , "Industrial city of northern France" .)