European country without any cause of disease (4)
I believe the answer is:
germ
'cause of disease' is the definition.
(I've seen this before)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for germ that I've seen before include "Cause of illness" , "Disease-causing microorganism" , "Bug" , "source of infection?" , "Origin" .)