The Collaborative International Dictionary of English v.0.48:

Falter \Fal"ter\, v. i. [imp. & p. p. Faltered; p. pr. & vb.
   n. Faltering.] [OE. falteren, faltren, prob. from fault.
   See Fault, v. & n.]
   1. To hesitate; to speak brokenly or weakly; to stammer; as,
      his tongue falters.
      [1913 Webster]

            With faltering speech and visage incomposed.
                                                  --Milton.
      [1913 Webster]

   2. To tremble; to totter; to be unsteady. "He found his legs
      falter." --Wiseman.
      [1913 Webster]

   3. To hesitate in purpose or action.
      [1913 Webster]

            Ere her native king
            Shall falter under foul rebellion's arms. --Shak.
      [1913 Webster]

   4. To fail in distinctness or regularity of exercise; -- said
      of the mind or of thought.
      [1913 Webster]

            Here indeed the power of disinct conception of space
            and distance falters.                 --I. Taylor.
      [1913 Webster]