The term "boarding" has several meanings, depending on its context.
1) In a general sense, boarding refers to the act of getting onto or riding in something, such as a vehicle, aircraft, train, ship, or bus. For example, one might say “I took an early morning flight and had to endure a long boarding process.”
2) Boarding can also refer to living arrangements at a school, college, or university where students live on campus in dormitories or residence halls. In this context, it means the act of moving into such accommodations for the academic year. For example, “I’m excited about starting my new job and boarding at the company's housing.”
3) Boarding can also refer to a type of horse riding competition where competitors jump over fences while on horseback. In this context, it means the act of riding in such an event or being involved with it as a spectator or participant. For example, “I’m planning to attend the boarding competition at the local equestrian center.”
4) Boarding can also refer to the action of moving onto something or going somewhere. In this context, it means the act of getting on or starting something. For example, "I'll be boarding my flight in an hour."