To inhale air. It is known to be very dangerous if unprepared while breathing.
Boy1: Hey man what're you doing?
Boy2: I'm breathing, but I'm being careful cuz i dont wanna get hurt.
Boy1: It's not worth it man, you could die. I don't even breathe anymore.
When something you don't realize is about to happen. And by the time you relaize it, it's too late.
It doesn't necessarily have to be fatal, because sometimes it is used in day-to-day instances
Man opens box, sees bomb:
Student1: *catches breathe* I can't believe I made it to the bus on time!
Student2: Where's your backpack?
Student1: O SHI-
You search "Where is Chuck Norris" on Google: