1. A flat, two-dimensional surface or level that is parallel to the ground or base, perpendicular to the vertical axis
The architect drew the design on a horizontal plane to show the building's layout.
O arquiteto desenhou o projeto num plano horizontal para mostrar a disposição do edifício.
2. In geometry and technical drawing, a plane that is at right angles to a vertical plane or line
In engineering, the horizontal plane is used as a reference for measurements.
Na engenharia, o plano horizontal é usado como referência para medições.