McCoy and Galloglass are both Anglicisations of terms from what language?
McCoy (surname) McCoy is a common surname of Scottish origin in the lands of Kintyre and then Irish (Gallowglass) origin. It is an Anglicisation of its Irish Gaelic form Mac Aodha, meaning "son of Aodh" (an old word for "Fire", a Celtic deity). It is particularly found in Ulster (Counties Antrim, Armagh and Monaghan) where many settled around the 13th century, having been Gallowglasses, and also in counties Limerick and Cork. Aoidh and Mac Aoigh were sometimes Anglicised as Hugh and McHugh.
Flaith A flaith (Irish) or flath (Modern Scottish Gaelic), plural flatha, in the Gaelic world, could refer to any member in general of a powerful family enjoying a high degree of sovereignty, and so is also sometimes translated as lord or aristocrat in the general sense, or can refer to sovereignty itself. Thus it did not usually refer to a specific position such as "Rí" (king) which any given "flaith" might or might not hold, allowing for the term to eventually develop the slightly alternative meaning of any hereditary high aristocrat who was understood to be subordinate to the king. In this later sense a "flaith" was similar to a magnate or Grandee.