Leave nothing but a sticky mess (3)
I believe the answer is:
goo
'a sticky mess' is the definition.
(thesaurus)
'leave nothing' is the wordplay.
'leave' becomes 'go' (to go is to depart or leave).
'nothing' becomes 'O' (O resembles 0).
'go'+'o'='GOO'
'but' acts as a link.
(Other definitions for goo that I've seen before include "Sticky substance (sl.)" , "syrup" , "mud, for example" , "Sentimentality (sl.)" , "Sticky wet material or sickly sentiment" .)