It has a driving connection (6)
I believe the answer is:
clutch
This could be a double definition.
'it' is the first definition.
The definition suggests a singular noun which matches the answer.
'a driving connection' is the second definition.
The definition and answer can be both acts as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
'has' acts as a link.
Can you help me to learn more?
(Other definitions for clutch that I've seen before include "Hold tight to the eggs" , "Grasp the brood of chickens" , "Grasp - eggs - car pedal" , "Grasp; group of eggs" , "Grip part of the car-engine" .)