Recorded in a wide range of spellings which are believed to include MacKelloch, MacKellough, MacCollough, McCollough, Coloe, Coloh, Collough, Kellough, Killough, Kiloe, Kilo, and Killow, this in a very confusing surname. Strictly speaking it can be Scottish, Irish and English, and in some cases in Ireland, possibly all three! In general terms for most name holders it is probably Gaelic, and certainly so when precceded by Mac or Mc, it is almost certainly a variant spelling of MacCulloch, an old name from Galloway. The meaning of the neame is the 'Wild Boar', from ancient word 'cullach'. However where the surname has often lost its prefix, it can be from Kelloe, an English surname from a vbillage in County Durham. This name was introduced into Ireland from about 1640, as part of the plan to increase the protestant population of the country. Over the centuries given that education was almost nil and few could even spell their name, Kelloe metamorphised into many forms as above, of which the most popular were probably the Gaelic looking Kellough and Killough. Examples of early recordings in surviving registers of Ireland include Marie Kelogh, who was christened at the church of St John the Evangelist, Dublin, on February 6th 1642, Anne Coloh, who was christened at St Michans church, Dublin, on June 5th 1666, and Jane Killough, who was christened at Finvoy, in County Antrim, of August 31st 1865.