Col. Bates moved barrier (8)
I believe the answer is:
obstacle
'barrier' is the definition.
(I've seen this in another clue)
'col bates moved' is the wordplay.
'moved' indicates anagramming the letters.
'col'+'bates'='colbates'
'colbates' anagrammed gives 'OBSTACLE'.
(Other definitions for obstacle that I've seen before include "It hinders or prevents advance" , "Anything that stands in the way" , "Progress blocker" , "stumbling block" , "hold-up" .)