Alas, terrible note on dish (5)
I believe the answer is:
salad
'dish' is the definition.
(salad is a kind of dish)
'alas terrible note on' is the wordplay.
'terrible' indicates an anagram.
'note' becomes 'd' (musical note**).
'on' says to put letters next to each other.
'alas' is an anagram of 'sala'.
'sala'+'d'='SALAD'
(Other definitions for salad that I've seen before include "Green, potato, Russian or Waldorf?" , "Counter serving cold vegetable dishes" , "Cold vegetable dish" , "Mainly raw cold dish" , "Cold dish of various vegetables," .)