It means to become unconscious. It can be used for fainting, but not only fainting. When someone passes out they are unconscious. "Why did he pass out? Oh, he got really drunk. He or she was "passed out drunk" is an expression that refers to someone getting so drunk that they become unconscious. "I started to fell very dizzy." Someone might ask: "Did you pass out?"

It is a pleasure to share English with you.

Hi, thanks to let me participate. Pass out means go outside. an example could be...A texting while driving tollme..pass out to check your car and driving it by 40 minutes .

Terry May gave the correct answer.