What term describes an object's position relative to the horizontal?

The term that describes an object's position relative to the horizontal is "Attitude." In the context of engineering, construction, and various technical fields, attitude refers to the angle or position of an object in relation to a defined reference point, often the horizon. It is crucial in ensuring that structures are level or achieving desired slopes in various applications.

Elevation typically refers to the height above a defined level, often sea level, and alignment pertains more to the arrangement or positioning of objects concerning each other or a certain axis. Orientation generally concerns the direction an object faces in space rather than its position relative to horizontal or vertical measures. Thus, when discussing the position of an object concerning the horizontal plane specifically, the most accurate term is "Attitude."