Reason famous cities govern centrally (6)

I believe the answer is:

motive

I'm a little stuck... Click here to teach me more about this clue!

'reason' is the definition.
(I know that motive is a type of reason)

I can't explain the remainder of the clue.

(Other definitions for motive that I've seen before include "Reason behind an action" , "Incitement to do something" , "Reason for doing something, perhaps a crime" , "Underlying purpose" , "Purpose - reason" .)

I've seen this clue in The Irish Times.

Want a hint initially instead of a full solution? Install my app