Kilian

Cillian or Killian
Family name
Meaning	Possibly " Little Church" or "strife"
Region of origin	Ireland
Language(s) of origin	Irish
Related names	Ó Cillín, Cillian, Ceallach, Kilian, Killion, Killeen

Killian or Cillian, as a given name, is an Anglicized version of the Irish name Cillín. Killian is the more radical anglisation of the name as there is no 'K' in the Gaelic alphabet.

Killian, as a surname, is found in both Ireland and Germany. It was originally spelled Ó Cillín in Irish before being Anglicized into Killeen as well as Killian. Spelling variations for Killian include Kilian, Killion, and others.

The name is said to derive from Saint Kilian, an Irish missionary to Germany in the 7th century, who, according to the Acta Sanctorum, was born in Mullagh, County Cavan, Ireland C.640. He departed for his mission to the continent with 12 Apostles from Kilmacologue in the parish of Tuosist, County Kerry, Ireland. In 689 he was martyred in Würzburg, Franconia, Germany and subsequently became the city's patron saint.

The most likely meaning of the name is "little church", a reference to someone prayerful or spiritual, cill meaning "church" in Gaelic while the suffix "-ín" is used affectionately to indicate a 'pet' or diminutive status. The Rev. Patrick Woulfe wrote that Cillian is the 'pet' diminutive of which means "war" or "strife".

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Wikipedia