Confuse fellow going back east (9)
I believe the answer is:
disorient
'confuse' is the definition.
(I know that disorient is a more specific form of the action confuse)
'fellow going back east' is the wordplay.
'fellow' becomes 'sid' (Sid is a man's name).
'going back' is a reversal indicator.
'east' becomes 'orient' (synonyms).
'sid' written backwards gives 'dis'.
'dis'+'orient'='DISORIENT'
(Other definitions for disorient that I've seen before include "Puzzle" , "Get confused" , "muddle" , "confuse" .)