Warnock
Warnock—This name is the anglicised form of McGilvernock in the 17th century, and the sept name is derived from one of the Graham family of Monteith, an ancient Pictish clan in Scotland. The name in Gaelic is Mac Gille-Mhearnoch, the son of the servant of St. Mernoch or Ernan. The name is found written as McIlvernock in Knapdale North, in 1751, in Valuation Rolls of Argyle. In Co. Antrim and Belfast City we find the form McVarnock.
Alphabetical Index of Anglicised Surnames in Ireland
See also Woulfe’s Irish Names and Surnames
… and O'Hart's Irish Pedigrees