The Collaborative International Dictionary of English v.0.48:

Halter \Hal"ter\, v. t. [imp. & p. p. Haltered (-t[~e]rd); p.
   pr. & vb. n. Haltering.]
   To tie by the neck with a rope, strap, or halter; to put a
   halter on; to subject to a hangman's halter. "A haltered
   neck." --Shak.
   [1913 Webster]