A motorist's club (6)
I believe the answer is:
driver
I believe this is a double definition.
'a motorist's' is the first definition.
(I've seen this before)
'club' is the second definition.
(type of golf club)
(Other definitions for driver that I've seen before include "Golf club for long shots" , "chauffeuse" , "Golf-club for a motorist" , "Motorist - golf club" , "Type of golf club" .)