Scandinavian capital (4)
'scandinavian capital' is the definition.
(capital of Norway, a Scandinavian country)
This is the entire clue.
(Other definitions for oslo that I've seen before include "European capital city (found in Czechoslovakia!)" , "Northern capital of Czechoslovakia?" , "Scandinavian city" , "Capital in throes of go-slow" , "City in Norway" .)
(Other definitions for kroner that I've seen before include "Scandinavian unit of money" , "Money units in Norway and Denmark" , "change in Denmark" , "Unit of money in Denmark and Norway" , "Danish CURRENCY" .)