To "evacuate ___" means to leave a place quickly because of a disaster or emergency. Some examples are:

• People "evacuate" a building when it's on fire.
• In science fiction movies and TV shows, the people on a space ship sometimes have to evacuate if their ship is attacked.
• You might have to evacuate your home if there's a hurricane, flood, or other natural disaster.

You can use the word "evacuate" with a word after it like this:

As the bombing started, people tried to evacuate the city.

Or you can avoid putting something after "evacuate":

As the bombing started, people tried to evacuate.