An aboard means being on or inside a vehicle, like a ship, plane, or train. This can also refer to a team or crew working together.
When we talk about being aboard something, we usually mean that someone is physically present on it, like riding a bus or sailing on a boat. For example, "She's flying home from Europe today, so she's aboard the plane right now." This phrase can also be used in situations where you're part of a group working together, like being aboard a team at work.
On board; into or within a ship or boat; hence, into or within a railway car.
Example: We all climbed aboard.
