/os'euh lay"sheuhn/ , n.
1. an act or instance of oscillating.
2. a single swing or movement in one direction of an oscillating body.
3. fluctuation between beliefs, opinions, conditions, etc.
4. Physics.
a. an effect expressible as a quantity that repeatedly and regularly fluctuates above and below some mean value, as the pressure of a sound wave or the voltage of an alternating current.
b. a single fluctuation between maximum and minimum values in such an effect.
5. Math.
a. the difference between the least upper bound and the greatest lower bound of the functional values of a function in a given interval.
b. Also called saltus . the limit of the oscillation in an interval containing a given point, as the length of the interval approaches zero.
[ 1650-60; oscillation- (s. of oscillatio ) a swinging, equiv. to oscillat ( us ) (see OSCILLATE) + -ion- -ION ]