Scrofula is bad behind London college (5,4)
I believe the answer is:
kings evil
'scrofula' is the definition.
(synonyms)
'bad behind london college' is the wordplay.
I cannot quite understand how this works, but
'bad' could be 'evil' (associated in meaning) and 'evil' is found within the answer.
'college' could be 'kings' (King's College London) and 'kings' is found in the answer.
No letters remain.
This may be the basis of the clue (or it may be nonsense).
'is' is the link.
Can you help me to learn more?
(Other definitions for kings evil that I've seen before include "Disease" , "2 [ROYAL] would not want to admit to?" , "old complaint" .)