As a Noun:
1. A journey to and from a place; a person who does such a journey in a day; a person who does such a journey every day to work and back. English = round trip, return journey; day tripper; commuter.
2. The movement to and fro between two locations (such as laps in a swimming pool).
3. A ticket to travel somewhere and then to come back. English = return ticket.
4. A day student at a school at which there are boarding students.
As a Verb or Adjective:
1. To go in one direction and then to come back in the opposite direction; to go to and fro.
2. To go to or to travel to a place and then to come back, to make a return journey; to go back and forth between places; to commute.
3. To go back and forth inside a room, a container, or between the extremities of some object (such as swimming laps in a pool).
4. To travel to a place and back from that place to the starting point on a return ticket; to make a return trip.
5. To be a day student at a school at which there are boarding students.