Fuss excessively about dinner's starter (2-2)
I believe the answer is:
to-do
'fuss' is the definition.
(I've seen this before)
'excessively about dinner's starter' is the wordplay.
'excessively' becomes 'too' (to too great a degree).
'about' indicates putting letters inside.
'starter' indicates taking the first letters.
The initial letter of 'dinners' is 'd'.
'too' enclosing 'd' is 'TO-DO'.
(Other definitions for to-do that I've seen before include "Kerfuffle" , "Fuss and bother" , "Quarrel" , "Flap" , "Bustle" .)