The crossword solution for the term STELLAR START is ASTRO, which is an abbreviation for Astronomy. Astronomy is the scientific study of celestial objects such as stars, planets, comets, and galaxies, as well as phenomena that originate outside the atmosphere of Earth. It is one of the oldest sciences, with its roots in ancient civilizations such as the Babylonians, Greeks, and Chinese. The term STELLAR START is often used to describe a successful beginning or launch of something, and in this case it is referring to the field of Astronomy.