(astronomy, physics, fiction, fantasy) Faster than light; having a speed greater than light.

The quality or condition of being superluminal.

In a superluminal manner; faster than the speed of light.

(astronomy) Having a very high luminosity

(astronomy) a type of supergiant spiral galaxy of the local universe that is much larger than most giant spiral galaxies, and whose stellar creation rate is much higher than typical spiral galaxies because it is more luminous

plural of superluminous spiral galaxy