angular coordinate(s)
Technical term in mathematics, referring to a coordinate that specifies the angle of a point in a polar or spherical coordinate system.
In polar coordinates, the angular coordinate is usually denoted by θ.
Cartesian coordinates; a coordinate system that uses perpendicular axes, in contrast to angular coordinates.
Compound of 角 (angle) and 座標 (coordinate). The exact historical derivation is uncertain, but the term is a straightforward technical coinage.