Proposition from those folk holding Scandinavian capital (7)
I believe the answer is:
theorem
'proposition' is the definition.
(I know that theorem is a type of proposition)
'those folk holding scandinavian capital' is the wordplay.
'those folk' becomes 'them' (those people).
'holding' indicates putting letters inside.
'scandinavian capital' becomes 'ore' (unit of currency Denmark and Norway).
'them' enclosing 'ore' is 'THEOREM'.
'from' is the link.
(Other definitions for theorem that I've seen before include "Mathematical formula" , "Deduced formula" , "Mathematical rule" , "A rule in algebra" , "Proof" .)