Orangemen's Day

noun
  1. July 12, an annual celebration in Northern Ireland and certain cities having a large Irish section, especially Liverpool, to mark both the victory of William III over James II at the Battle of the Boyne, July 1, 1690, and the Battle of Augbrim, July 12, 1690.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018