waver

Etymology

From Middle English waveren, from Old Norse vafra (“to flicker”), akin to Old English wǣfre (“restless, wavering”). Related to wave.

verb

1. (intransitive) To sway back and forth; to totter or reel.
   Flowers wavered in the breeze.
   1523–1525, Jean Froissart, John Bourchier, 2nd Baron Berners (translator), Froissart's Chronicles With banners and pennons wavering with the wind.
2. (intransitive) To flicker, glimmer, quiver, as a weak light.
3. (intransitive) To fluctuate or vary, as commodity prices or a poorly sustained musical pitch.
4. (intransitive) To shake or tremble, as the hands or voice.
   His voice wavered when the reporter brought up the controversial topic.
5. (intransitive) To falter; become unsteady; begin to fail or give way.
   ...and that when a man was in the wrong his courage wavered, and his nerves became unsteady, and so he couldn't fight to advantage and was easily overcome. 1903, Bill Arp, From the Uncivil War to Date
   Although they believe they can overhaul their 2-0 deficit, they cannot afford to be as lethargic as this at Camp Nou, and the time is surely approaching when Manuel Pellegrini's faith in Martín Demichelis wavers. 9 March 2014, Jacob Steinberg, “Wigan shock Manchester City in FA Cup again to reach semi-finals”, in The Guardian
6. (intransitive) To be indecisive between choices; to feel or show doubt or indecision; to vacillate.
   Despite all the terrible things that happened to her, she never wavered from her beliefs.
   Javik: Do not waver. Victory is never won without difficult choices. Shepard: I'll do whatever it takes. I didn't come this far to back down. 2012, BioWare, Mass Effect 3: From Ashes (Science Fiction), Redwood City: Electronic Arts, PC, scene: Earth (Priority: Earth)

noun

1. An act of wavering, vacillating, etc.
2. Someone who waves, enjoys waving, etc.
   I felt encouraged by all the enthusiastic wavers in the crowd.
   The Fourth of July brings out all the flag wavers.
   Johnny is such a little waver; everyone who passes by receives his preferred greeting.
3. Someone who specializes in waving (hair treatment).
4. A tool that accomplishes hair waving.
5. (UK, dialect, dated) A sapling left standing in a fallen wood.
   50 to 80 Wavers or Saplings, on each acre 1813, John Farey, General View of the Agriculture and Minerals of Derbyshire