* The crowd waved enthusiastically as the band took the stage.
* She waved goodbye to her friend as the train pulled away.
* The flag waved proudly in the wind.
* The dog waved its tail excitedly.
* The sea waves crashed against the shore. (This one uses "waves" both as a noun and a verb)
The verb "wave" can be used in various contexts, often to describe a movement of something back and forth or up and down, often with a signal or gesture.