Oscillate \Os"cil*late\ ([o^]s"s[i^]l*l[=a]t), v. i. [imp. & p. p. {Oscillated} ([o^]s"s[i^]l*l[=a]`t[e^]d); p. pr. & vb. n. {Oscillating} ([o^]s"s[i^]l*l[=a]`t[i^]ng).] [L. oscillare to swing, fr. oscillum a swing, a little mask or puppet made to be hung from trees and swing in the wind, prob. orig., a little mouth, a dim. from os mouth. See {Oral}, and cf. {Osculate}.] 1. To move backward and forward; to vibrate like a pendulum; to swing; to sway.
2. To vary or fluctuate between fixed limits; to act or move in a fickle or fluctuating manner; to change repeatedly, back and forth.
The amount of superior families oscillates rather than changes, that is, it fluctuates within fixed limits. --De Quincey.
Democrats have launched an ambitious program to identify the 16 million or so voters who oscillate between Republican and Democratic candidates.