Restaurant may add one allegation after function (7,6)
I believe the answer is:
service charge
'restaurant may add one allegation' is the definition.
I can't judge whether this definition defines the answer.
'function' is the wordplay.
I cannot really see how this works, but
'function' could be 'service' (servicing is a kind of functioning) and 'service' is present in the answer.
The remaining letters 'charge' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
'after' is the link.
Can you help me to learn more?
(Other definitions for service charge that I've seen before include "Restaurant bill add-on" , "Maintenance fee on leased property" , "Amount added to a bill in a restaurant" , "Additional restaurant fee" , "Restaurant bill addition" .)