Drive to Oslo regularly (4)
I believe the answer is:
tool
'drive' is the definition.
(thesaurus)
'to oslo regularly' is the wordplay.
'regularly' indicates alternate letters (regularly take one letter, leave next etc.).
The alternating letters of 'oslo' are 'ol'.
'to'+'ol'='TOOL'
(Other definitions for tool that I've seen before include "Pawn" , "Instrument, implement" , "Gun" , "Implement - agency" , "Weapon" .)