Silly fools start off in capital (4)
I believe the answer is:
oslo
'capital' is the definition.
(capital of Norway)
'silly fools start off' is the wordplay.
'silly' is an anagram indicator.
'start off' means to remove the first letter (the start of the word is taken off).
'fools' with its first letter taken away is 'ools'.
'ools' is an anagram of 'OSLO'.
'in' acts as a link.
(Other definitions for oslo that I've seen before include "Former Christiania" , "Norwegian capital" , "Capital in throes of go-slow" , "European capital, known until 1924 as Christiania" , "Nordic city" .)