Usually, cylindrical coordinates. a member of a system of coordinates for locating a point in space by its polar coordinates and its perpendicular distance to the polar plane.
British Dictionary definitions for cylindrical coordinates
cylindrical coordinates
plural noun
1.
three coordinates defining the location of a point in three-dimensional space in terms of its polar coordinates (r, θ) in one plane, usually the (x, y) plane, and its perpendicular distance, z, measured from this plane