ALL meanings of radial velocity
ra·di·al ve·loc·i·ty
R r - noun radial velocity the component of the motion of a star away from or toward the earth along its line of sight, expressed in miles or kilometers per second and determined by the shift in the wavelength of light emitted by the star. 1
- noun radial velocity the component of the velocity of an object, esp a celestial body, directed along a line from the observer to the object 0