Plague source unfortunately touring capital in Germany (7)
I believe the answer is:
scourge
'plague' is the definition.
(I've seen this in another clue)
'source unfortunately touring capital in germany' is the wordplay.
'unfortunately' is an anagram indicator (a bad or unfortunate spelling).
'touring' is an insertion indicator (tour can mean to go around).
'capital in' says to take the initial letters.
The first letter of 'germany' is 'g'.
'source' with letters rearranged gives 'scoure'.
'scoure' placed around 'g' is 'SCOURGE'.
(Other definitions for scourge that I've seen before include "Flagellate" , "Person/thing causing great suffering; whip" , "Cause of great affliction" , "Whip, flog" , "Pest" .)