Moke to overtake and head off (3)
I believe the answer is:
ass
'moke' is the definition.
(I've seen this before)
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for ass that I've seen before include "Small hoofed animal" , "Charlie" , "Braying animal" , "Blockhead" , "Quadruped; fool" .)