Folly, nonsense (7)
I believe the answer is:
madness
I believe this clue is a double definition.
'folly' is the first definition.
(I know that folly can be written as madness)
'nonsense' is the second definition.
(thesaurus)
(Other definitions for madness that I've seen before include "Dementia" , "Group" , "fury" , "Utter foolishness" , "Irrationality" .)