space
The three-dimensional field in which objects and events occur and have relative position and direction, especially a portion of that field set apart in a given instance or for a particular purpose. 2. The area at the corner of a turning stair, limited approximately by lines drawn through the newel or angle perpendicular to each of the two strings, or by such a line and one drawn in prolongation of the string. Commonly used as synonymous with pace. (Sturgis, 1900)