Knight one's taken back with rook (3)
I believe the answer is:
sir
'knight' is the definition.
(a knight has the title Sir)
'one's taken back with rook' is the wordplay.
'one's' becomes 'is' (Roman numeral).
'taken back' says the letters should be written in reverse.
'with' says to put letters next to each other.
'rook' becomes 'R' (chess abbreviation).
'is' backwards is 'si'.
'si'+'r'='SIR'
(Other definitions for sir that I've seen before include "... ___ John Major" , "Feted fellow" , "Title of Kt or Bart" , "Male title of respect" , "Title of 1 across" .)