Verb
1. pause or hold back in uncertainty or unwillingness;
"Authorities hesitate to quote exact figures"2. be unsure or weak;
"Their enthusiasm is faltering"3. move hesitatingly, as if about to give way
4. move or sway in a rising and falling or wavelike pattern;
"the line on the monitor vacillated"5. move back and forth very rapidly;
"the candle flickered"6. sway to and fro
7. give off unsteady sounds, alternating in amplitude or frequency