waver (http://definr.com/waver)

     n 1: someone who communicates by waving
     2: the act of pausing uncertainly; "there was a hesitation in
        his speech" [syn: hesitation, falter, faltering]
     3: the act of moving back and forth [syn: flutter, flicker]
     v 1: pause or hold back in uncertainty or unwillingness:
          "Authorities hesitate to quote exact figures." [syn: hesitate,
     2: be unsure or weak; "Their enthusiasm is faltering" [syn: falter]
     3: move hesitatingly, as if about to give way [syn: falter]
     4: move in an unstable manner [syn: fluctuate, vacillate]
     5: move back and forth very rapidly, as of a candle [syn: flicker,
         flitter, flutter, quiver]
     6: sway to and fro [syn: weave]
     7: give off unsteady sounds, alternating in amplitude or
        frequency [syn: quaver]