McCoy and Galloglass are both Anglicisations of terms from what language?
Gallowglass The gallowglasses (also spelt galloglass, gallowglas or galloglas; from Irish: "gall óglaigh" meaning foreign warriors) were a class of elite mercenary warriors who were principally members of the Norse-Gaelic clans of Scotland between the mid 13th century and late 16th century. As Scots, they were Gaels and shared a common background and language with the Irish, but as they had intermarried with the 10th century Norse settlers of western Scotland, the Irish called them "Gall Gaeil" ("foreign Gaels").
Grog Grog is any of a variety of alcoholic beverages. The word originally referred to a drink made with water and rum, which British Vice Admiral Edward Vernon introduced into the naval squadron he commanded in the West Indies on 21 August 1740. Vernon wore a coat of grogram cloth and was nicknamed "Old Grogram" or "Old Grog". Merriam Webster's Collegiate Dictionary, which agrees with this story of the word's origin, states that the word "grog" was first used in this sense in 1770, though other sources cite 1749.