Runs in Paris and is second — tries again? (7)
I believe the answer is:
retests
'tries again?' is the definition.
('tests' can be a synonym for 'tries' so perhaps 'retests' is OK for 'tries again')
'runs in paris and is second' is the wordplay.
I cannot really understand how this works, but
'runs' could be 'tests' ('test' can be a synonym of 'run') and 'tests' is found within the answer.
'second' could be 're' (prefix meaning second in eg review, re-education) and 're' is found within the answer.
This accounts for all the letters.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for retests that I've seen before include "Again investigates" , "further examinations" .)