waver

(noun) someone who communicates by waving.

(noun) the act of pausing uncertainly. Synonyms: hesitation, falter, faltering. Example: "There was a hesitation in his speech."

(noun) the act of moving back and forth. Synonyms: flutter, flicker.

(verb) pause or hold back in uncertainty or unwillingness. Synonyms: hesitate, waffle. Example: "Authorities hesitate to quote exact figures."

(verb) be unsure or weak. Synonyms: falter. Example: "Their enthusiasm is faltering."

(verb) move hesitatingly, as if about to give way. Synonyms: falter.

(verb) move or sway in a rising and falling or wavelike pattern. Synonyms: fluctuate, vacillate. Example: "The line on the monitor vacillated."

(verb) move back and forth very rapidly. Synonyms: flicker, flitter, flutter, quiver. Example: "The candle flickered."

(verb) sway to and fro. Synonyms: weave.

(verb) give off unsteady sounds, alternating in amplitude or frequency. Synonyms: quaver.