oscillate

v. vary regularly between two positions; vacillate between two opinions; fluctuate between high and low values; swing predictably between two extremes

For other uses, see oscillator (disambiguation) Oscillation is the variation, typically in time, of some measure about a central value (often a point of equilibrium) or between two or more different states. Familiar examples include a swinging pendulum and AC power. The term vibration is sometimes used more narrowly to mean a mechanical oscillation but sometimes is used to be synonymous with "oscillation." Oscillations occur not only in physical systems but also in biological systems and in human society.
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Verb
1. be undecided about something; waver between conflicting positions or courses of action; "He oscillates between accepting the new position and retirement"
(synonym) hover, vibrate, vacillate
(hypernym) hesitate, waver, waffle
(hyponym) shillyshally
(derivation) oscillation
2. move or swing from side to side regularly; "the needle on the meter was oscillating"
(synonym) vibrate
(hypernym) swing, sway
(hyponym) hunt
(derivation) cycle, oscillation

v. oscillate, fluctuate, sway, swing, rock, balance, seesaw, dither, waver, flicker, vacillate, wobble, wabble, jiggle, range

(v. i.)
To vary or fluctuate between fixed limits; to act or move in a fickle or fluctuating manner; to change repeatedly, back and forth.
  

(v. i.)
To move backward and forward; to vibrate like a pendulum; to swing; to sway.