galloglass
Concise Oxford English Dictionary © 2008 Oxford University Press:
galloglass /ˈgalə(ʊ)glɑːs/ (also gallowglass)
▶noun historical (in Ireland) a mercenary or member of a special class of soldiers in the service of a chieftain.
– origin C15: from Ir. gallóglach, from gall ‘foreigner’ and óglach ‘youth, servant, warrior’.
'galloglass' also found in these Oxford entries:

