Whippletree /(?)/

Whip·ple·tree

Whippletree

n.
  1. The pivoted or swinging bar to which the traces, or tugs, of a harness are fastened, and by which a carriage, a plow, or other implement or vehicle, is drawn; a whiffletree; a swingletree; a singletree. See Singletree.
    [People] cut their own whippletree in the woodlot.
  2. The cornel tree. (Bot.)