- A term applied to some characteristic magnitude whose
value, invariable as long as one and the same function, curve, surface,
etc., is considered, serves to distinguish that function, curve,
surface, etc., from others of the same kind or family. - Specifically (Conic Sections), in the ellipse and
hyperbola, a third proportional to any diameter and its conjugate, or
in the parabola, to any abscissa and the corresponding ordinate. - The ratio of the three crystallographic axes which
determines the position of any plane; also, the fundamental axial ratio
for a given species.
parameter Mathematically, parameter is a constant in an equation that defines the form of the curve; in psychology, it is a constant that defines the curve of a psychological function