Arrange to leave (3,3)
I believe the answer is:
set out
I believe this is a double definition.
'arrange' is the first definition.
(setting out is a kind of arranging)
'leave' is the second definition.
(setting out is a kind of leaving)
'to' is the link.
(Other definitions for set out that I've seen before include "Start journey, get going" , "State" , "Depart" , "Go forth" , "Begin a journey or arrange display" .)