Stop of French Express not right (6)
I believe the answer is:
detain
'stop' is the definition.
(I've seen this before)
'of french express not right' is the wordplay.
I cannot really understand how this works, but
'of french' could be 'de' ('of' in French) and 'de' is present in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for detain that I've seen before include "Hang on to" , "Delay, arrest" , "Hold or keep back, maybe for questioning" , "Ate din (anag.)" , "Keep (someone) held in custody" .)