Aims to keep the French Sabbath going for ever (7)
I believe the answer is:
endless
'going for ever' is the definition.
I can't tell whether this defines the answer.
'aims to keep the french sabbath' is the wordplay.
'aims' becomes 'ends' (I've seen this before).
'to keep' indicates putting letters inside.
'the french' becomes 'le' ('the' in French).
'sabbath' becomes 's'.
'ends' enclosing 'le' is 'endles'.
'endles'+'s'='ENDLESS'
Can you help me to learn more?
(Other definitions for endless that I've seen before include "Eternal - unbroken" , "Eternal or interminable" , "Unceasing" , "Non-stop" , "Continual" .)