A vest is a sleeveless piece of clothing worn over a shirt, covering your chest and back but leaving your arms free. Men might wear a formal vest as part of a three-piece suit, while someone working outdoors might wear a puffy vest to stay warm without restricting their arm movement. You've probably seen bright orange or yellow safety vests worn by construction workers or crossing guards so they're visible to drivers.

The word also appears in several important phrases. When something vests, it becomes officially yours. If your grandmother sets up a trust fund that vests when you turn 18, the money legally becomes yours on that birthday. When employees receive stock options that vest over time, they earn full ownership gradually, often as a reward for staying with the company.

You might hear about someone having a vested interest in something, meaning they have a personal stake in the outcome. If your parents own a bakery, you have a vested interest in its success because your family depends on it. A student who helped plan a field trip has a vested interest in good weather that day.

The phrase vest authority means to give someone official power, like when a principal vests a teacher with the authority to make decisions about classroom rules.