Plain English Meaning

How heavy the airplane is — the pull of gravity on everything in and on it. This downward pull is one of the four forces acting on the airplane in flight, and lift has to match it to stay level.

Full Definition

The downward force exerted on an airplane due to gravity acting on its mass, including the airframe, fuel, occupants, and cargo. Weight acts vertically toward the center of the earth and must be balanced by lift for the airplane to maintain level flight.

Context Anchor

Seen in final approach, landing performance, and weight-and-balance discussions, especially when deciding whether the airplane is at a safe weight for and what or distance to expect.