Waver

From Old Norse vafra ("to flicker").

Full definition of waver

(intransitive) To sway back and forth; to totter or reel.Flowers wavered in the breeze.

Ld. BernersWith banners and pennons wavering with the wind.
Sir Walter ScottThou wouldst waver on one of these trees as a terror to all evil speakers against dignities.

(intransitive) To flicker, glimmer, quiver, as a weak light.
(intransitive) To fluctuate or vary, as commodity prices or a poorly sustained musical pitch.
(intransitive) To shake or tremble, as the hands or voice.His voice wavered when the reporter brought up the controversial topic.
(intransitive) To falter; become unsteady; begin to fail or give way.

1903, Bill Arp, From the Uncivil War to Date...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.
2014, Jacob Steinberg, "Wigan shock Manchester City in FA Cup again to reach semi-finals", The Guardian, 9 March 2014: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 MartÃn Demichelis wavers.

(intransitive) To be indecisive between choices; to feel or show doubt or indecision; to vacillate.

(plural wavers)

An act of wavering, vacillating, etc.
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.
Someone who specializes in waving (hair treatment).
A tool that accomplishes hair waving.
(UK, dialect, dated) A sapling left standing in a fallen wood.
A darkwaver; a fan of darkwave music.