Pulp has gone over the top of everything (5)
I believe the answer is:
paste
'pulp' is the definition.
(thesaurus)
'gone over the top of everything' is the wordplay.
'gone' becomes 'past' ('past' can be similar in meaning to 'gone').
'over' means one lot of letters go next to another.
'the top of' says to take the initial letters.
The initial letter of 'everything' is 'e'.
'past'+'e'='PASTE'
'has' is the link.
(Other definitions for paste that I've seen before include "Adhesive, for wallpaper perhaps" , "Adhesive, for wallpaper say" , "Adhesive gum" , "Creamy, sticky, or doughy mixture" , "It is used to stick wallpaper" .)