over

Something is over when it has finished, usually referring to an event.

Example: When the movie was over we left the movie theater.

In a location above something.

Example: He stepped over the dog.

From one side to the other.

Example: They went over the bridge.

A number divided by another.

Example: Eight over two is four.

If you do something over, you do it again.

Example: That looks really bad. I think we need to do it over.