To depart means to leave or go away from a place. When a train departs from the station, it pulls away and begins its journey. When guests depart after a party, they say goodbye and head home. Airlines post departure times showing when planes will leave the airport.

The word often carries a sense of intentional leaving, not just wandering off. You might casually leave your backpack in a classroom by accident, but you depart from school at the end of the day with purpose. Explorers depart on expeditions. Ships depart from harbors. Students depart for summer vacation.

Departure is the noun form. A flight's departure might be delayed by weather. A family's departure for their road trip might be earlier than planned to beat traffic.

The word can also mean to change from what's normal or expected. A teacher might depart from the usual lesson plan to discuss something interesting that came up in class. A director might depart from the book when making a movie, changing certain details or scenes. This meaning suggests moving away from a standard or tradition, just like physically departing means moving away from a place.