A football team maybe back in French city (3)
I believe the answer is:
aix
'french city' is the definition.
Although both the answer and definition are singular nouns, I can't see how one could define the other.
'a football team maybe back' is the wordplay.
'football team maybe' becomes 'XI' (Roman numerals for eleven).
'back' says the letters should be written in reverse.
'xi' backwards is 'ix'.
'a'+'ix'='AIX'
'in' is the link.
Can you help me to learn more?
(Other definitions for aix that I've seen before include "-- -la-Chapelle (Aachen)" , "Whither Ghent good news (Browning)" , "Various French towns; sounds like pains" .)