Calm Bill fills dish (7)
I believe the answer is:
placate
'calm' is the definition.
(I know this)
'bill fills dish' is the wordplay.
'bill' becomes 'ac' (short for account).
'fills' indicates putting letters inside.
'dish' becomes 'plate' (plate is a kind of dish).
'ac' inserted within 'plate' is 'PLACATE'.
(Other definitions for placate that I've seen before include "Make calm, conciliate" , "Mollify, appease" , "'Pacify, appease (7)'" , "Pale cat could pacify" , "Mollify, calm down" .)