Neil "Neil" is a reduced form of the surname "McNeil" (from the Gaelic "Mac Néill", "son of "Niall""), or variant form the surname of Neill (from the Irish "Ó Néill" or the Scottish Gaelic "Mac Néill", meaning "descendant of "Niall"" and "son of "Niall"". The name passed from Ireland to Scotland where it had the "Mc/Mac" prefix. Some Scottish McNeill's returned to Ireland in the 14th century and are associated with "MacNeill", "MacGreal", "MacReill", and "Mag Reil" surnames. The Manx version of the name is "Kneal" (1598), "Kneale" (1655), or "Kneel" (1636). It evolved from McNelle (1408) and MacNeyll (1430) becoming
Eolais mac Biobhsach manuscripts going back almost two hundred years. O'Donovan claimed the family name ( "descendent of Eolais") is still found anglicised as "Olus" or "Olis". two instances of the surname corrupted as "Oelase" and "Olase", are found in the Irish Fiants for Leinster. The surname must be very rare. Eolais mac Biobhsach Eolais "mac Biobhsach" (alias " "knowledge", anglicized "Wallis", "Olis" or "Olus" ) was a chieftain of 10th century Gaelic Ireland. He is noted as the first "full chieftain of Conmaicne Réin". His descendants, "the Muintir Eolais", expanded into the territory of present day south county Leitrim, and parts of