The Collaborative International Dictionary of English v.0.48:

Bullock \Bul"lock\, v. t.
   To bully. [Obs.]
   [1913 Webster]

         She shan't think to bullock and domineer over me.
                                                  --Foote.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Bullock \Bul"lock\, n. [AS. bulluc a young bull. See Bull.]
   1. A young bull, or any male of the ox kind.
      [1913 Webster]

            Take thy father's young bullock, even the second
            bullock of seven years old.           --Judges vi.
                                                  25.
      [1913 Webster]

   2. An ox, steer, or stag.
      [1913 Webster]

WordNet (r) 3.0 (2006):

bullock
    n 1: young bull
    2: castrated bull [syn: bullock, steer]