/*Meaning of Name*/ Edit
Instead of putting this on both Bastien pages separately, putting it here for whoever wants to correct the name definition on both pages. Not good at concise so will just give you the big three.
Edgar' Name page  is the best if you are looking for nicknames ... which often become names in their own right. There could be other meanings or more nuanced meanings for Sebastien - collecting names right now, will do a proper job for this name later, but that is not need here. From Bastian listing:
"Bastian is a shortened form of the name Sebastian, which comes from a Greek name meaning “Man from Sebasta,” when Sebasta was a place derived from Augustus, meaning “Revered.”
St. Sebastian was a popular saint during the Middle Ages, especially in Spain, France, and Germany. His name was often bestowed upon children, often in the shortened form of Bastian, (or Bastien, or Bestian)."
From Sebastian listing:
"Sebastian, being the name of a well-known 3rd-century Roman martyr saint, was popular during the Middle Ages (artists, especially, were fond of depicting his dramatic, arrow-filled death). Although it was popluar in Spain, France, and Germany (often as Bastian, Bastien, or Bestian), Sebastian was rather less common in England (except in Cornwall, where it was imported from France)."
From Behind the Name :
"From the Latin name Sebastianus which meant "from Sebaste". Sebaste was the name a town in Asia Minor, its name deriving from Greek σεβαστος (sebastos) "venerable" (a translation of Latin Augustus, the title of the Roman emperors). Saint Sebastian was a 3rd-century Roman soldier martyred by arrows after it was discovered he was a Christian. Due to the saint's popularity, the name came into general use in medieval Europe, especially in Spain and France. It was also borne by a 16th-century king of Portugal who died in a crusade against Morocco.
Sébastien, Bastien (French),"
From 20000 Names :
BASTIEN: Short form of French Sébastien, meaning "from Sebaste." SÉBASTIEN: French form of Latin Sebastianus, meaning "from Sebaste." 190.SEBASTIJAN: Slovene form of Greek Sebastianos, meaning "from Sebaste." 187.SEBASTIANOS (Σεβαστιανός): Greek name meaning "from Sebaste," a city in Pontus named after Augustus Cæsar (from Greek sebastos "venerable"). (Vaudree (talk) 16:24, October 26, 2015 (UTC))
From Strong's :
4575 - sebastos - from sebazomai - sebazomai 4573; venerable (august), i.e. (as noun) a title of the Roman Emperor, or (as adjective) imperial:--Augustus(-').
4573 - sebazomai - middle voice from a derivative of sebomai - sebomai 4576; to venerate, i.e. adore:--worship.
4576 - sebomai - middle voice of an apparently primary verb; to revere, i.e. adore:--devout, religious, worship.
From Wiktionary  - note that b=v for Greek words transcribed into the English alphabet:
From σεβαστός (sebastós, “venerable, reverend, august”), from σέβας (sébas, “awe, reverence, dread”),
σέβας • (sévas) - 1.respect
σεβασμός • (sevasmós) m (plural σεβασμοί) 1.respect
Related terms σέβομαι (sévomai, “to respect”) σεβάσμιος (sevásmios, “venerable”) σεβαστός (sevastós, “respected, venerable”)