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.
The Sun is in conflict with those who are ruled by Saturn, and Saturn is in conflict with those ruled by the Sun. - Picatrix (Andalusia, ~1000.AD)