oscillate
🇺🇸
/ˈɑːsɪleɪt/
🇬🇧
/ˈɒsɪleɪt/
to move back and forth between two points or states
Her emotions oscillated between sadness and happiness.
to move regularly between two places or positions
The pendulum on the clock oscillated back and forth.
to change regularly in strength or direction
The signal strength oscillated as we moved further away.