When a man with a gun walks into a bank and says, "Give me all your money," that's a heist or a robbery at gunpoint.
Heist, pronounced "hīst," is a slang word for an armed robbery. It's also a slang word used to describe the act of stealing or breaking into someone's house to steal their stuff. In other words, it's a burglary. Heist can also act as a verb: "If you've heisted a diamond ring, you've stolen it."