Forbid one to leave peaceful meal (7)
I believe the answer is:
banquet
'meal' is the definition.
(banquet is a kind of meal)
'forbid one to leave peaceful' is the wordplay.
I cannot really understand how this works, but
'forbid' could be 'ban' (banning is a kind of forbiding) and 'ban' is found within the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for banquet that I've seen before include "Grand meal" , "Elaborate meal" , "Lavish feast" , "A fancy feast" , "Sumptuous meal" .)