os ‧ cil ‧ la ‧ tion /ˌɒsəˈleɪʃ ə n, ˌɒsɪˈleɪʃ ə n $ ˌɑː-/ BrE AmE noun [uncountable and countable]
1 . formal oscillations are frequent changes between two extreme amounts or limits
oscillation in/of
oscillations in the value of the dollar
oscillation between
oscillating between growth and decline
2 . formal oscillations are frequent changes between one feeling or attitude and another:
The drug causes oscillations of mood in some people.
3 . technical a regular movement of something from side to side:
the oscillations of a pendulum
4 . technical a regular change in direction of an electrical current