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galloglass

American  
[gal-oh-glas, -glahs] / ˈgæl oʊˌglæs, -ˌglɑs /
Or gallowglass

noun

Irish History.
  1. a follower and supporter of or a soldier owing allegiance to an Irish chief.


galloglass British  
/ ˈɡæləʊˌɡlɑːs /

noun

  1. a heavily armed mercenary soldier, originally Hebridean (Gaelic-Norse), maintained by Irish and some other Celtic chiefs from about 1235 to the 16th century

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of galloglass

1505–15; < Irish gallóglách, equivalent to gall a stranger, foreigner + óglach a youth, soldier, servant, derivative of Old Irish óac, óc young