Scorned AA invention twice by the road, ultimately (4-6)
I believe the answer is:
pooh-poohed
'scorned' is the definition.
('pooh-pooh' can be a synonym of 'scorn')
'aa invention twice by the road ultimately' is the wordplay.
'aa invention' becomes 'pooh' (Winnie the Pooh, character created by AA Milne).
'twice' says to double the letters.
'by' is a charade indicator (letters next to each other).
'ultimately' indicates one should take the final letters.
The last letters of 'the road' are 'ed'.
'pooh' duplicated is 'poohpooh'.
'poohpooh'+'ed'='POOH-POOHED'
(Another definition for pooh-poohed that I've seen is " Dismissed contemptuously".)