Pull domesticated ox round rear of barn (4)
I believe the answer is:
yank
'pull' is the definition.
(yanking is a kind of pulling)
'domesticated ox round rear of barn' is the wordplay.
'domesticated ox' becomes 'yak' (I've seen this before).
'round' is an insertion indicator.
'rear of' suggests the final letters.
The final letter of 'barn' is 'n'.
'yak' enclosing 'n' is 'YANK'.
(Other definitions for yank that I've seen before include "Pull sharply" , "pluck" , "An informal American - tug him" , "Term for an American" , "American native" .)