Eradicated disease (8)
I believe the answer is:
smallpox
'eradicated disease' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for smallpox that I've seen before include "Highly contagious viral disease with fever and skin pustules that leave permanent scars" , "Acute viral disease, technical name variola" , "Viral disease, now almost eradicated by vaccination" .)