Sebastian traces to a Greek honorific meaning "venerable" or "revered," later adapted into Latin as a personal name. Historically it described someone worthy of respect by standing, not necessarily by age, and it has carried a dignified, formal air through centuries of use across several European languages.
If the ascendant be fortunate, and the lord thereof unfortunate, it indicates a sound and healthful body, but an afflicted mind. But if the contrary happen, judge the contrary. - William Lilly (1602.-1681.)