Variant spelling of Sebastian, from Greek 'sebastos' meaning 'venerable' or 'revered,' a title like Augustus.
Sebastain is a variant spelling of Sebastian, a name with deep roots in both classical geography and Christian martyrology. The Latin Sebastianus derives from the Greek Sebastianos, 'man from Sebastia' — a city in ancient Pontus, in modern Turkey, whose own name came from 'sebastos,' the Greek rendering of the Latin 'augustus,' meaning venerable or revered. The name thus carries imperial dignity at its very etymological foundation, even as its most famous historical bearer embodied something far more vulnerable and human.
Saint Sebastian was a Roman soldier and Christian martyr put to death during the reign of Diocletian, around 288 AD. According to tradition, he survived being shot through with arrows — a scene that became one of the most painted subjects of the Italian Renaissance, depicted by Mantegna, Botticelli, Titian, and El Greco among many others. Sebastian's combination of physical beauty, military bearing, and spiritual courage made him an enduring icon, and his feast day on January 20 has been observed continuously since late antiquity.
The name spread through Catholic Europe with remarkable consistency, producing Bach (Johann Sebastian Bach), Canova, and in literature the unforgettable Sebastian Flyte of Evelyn Waugh's Brideshead Revisited — a character whose languid charm and doomed beauty seem to echo the martyr's paradoxical combination of strength and fragility. The spelling Sebastain — transposing the 'i' and 'a' — appears as a phonetic variant in communities where the name was transmitted orally before it was written, a reminder that names live first in the mouth and only secondarily on the page.