Meaning: Its source is Ceallach, an Irish Gaelic name meaning "Brilliant hair."

Languages: This boy's name is used in Irish Gaelic.

Alternative Spellings: Killian

Source Forms: Ceallach

Narrative: Some authorities prefer the meaning ''church-goer.''

Meaning: Its source is Ceallach, an Irish Gaelic name meaning "Brilliant hair."

Languages: This girl's name is used in Irish Gaelic.

Narrative: Another possible meaning of the source of this name is ''church-goer.''