Way of acting (6)
I believe the answer is:
method
This clue is a double definition.
'way' is the first definition.
(method is a kind of way)
'acting' is the second definition.
(I know that method is a type of acting)
'of' is the link.
(Other definitions for method that I've seen before include "particular procedure" , "'Means, way of achieving (6)'" , "Orderliness; procedure" , "Scheme; orderliness" , "System, perhaps even in madness" .)