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},
           {waffle}]
     2: be unsure or weak; "Their enthusiasm is faltering" [syn: {falter}]
     3: move hesitatingly, as if about to give way [syn: {falter}]
     4: move or sway in a rising and falling or wavelike pattern;
        "the line on the monitor vacillated" [syn: {fluctuate}, {vacillate}]
     5: move back and forth very rapidly; "the candle flickered"
        [syn: {flicker}, {flitter}, {flutter}, {quiver}]
     6: sway to and fro [syn: {weave}]
     7: give off unsteady sounds, alternating in amplitude or
        frequency [syn: {quaver}]
Source: WordNet® 2.0