" gallowglass "

[Noun]  | "gal*low*glass" | \ ˈga-lō-ˌglas \

1: a mercenary or retainer of an Irish chief

2: an armed Irish foot soldier

Origin: circa 1515 ;

 Borrowed from Irish gallóglach "soldier from a Scottish clan in the service of an Irish chief," from gall "Gaul, Scandinavian invader, foreigner" (going back to Middle Irish, borrowed from Latin Gallus "a {see: |gaul|Gaul}") + óglach "young man, warrior, soldier," going back to Middle Irish óclach, óglaech, originally derivative (probably after echlach "messenger, attendant," midlach "man incapable of bearing arms, coward") of óc "young," going back to Old Irish óac, going back to Celtic *yowanko- (whence also Welsh ieuanc "young," Breton yaouank), going back to Indo-European *h2i̯̯u-h2n-ḱo-{mat|young:1|} ;

  * Note : The final -ss in the English form is difficult to explain. It may be an English plural -s added superfluously to the Irish plural gallóglaigh, though one would expect this to be evident in early use of gallowglass as a plural. The apparent first known occurrence of the word, however, is galloglasseis, which already shows a singular galloglas(s) as the base form.;

[Noun]  | "gallowglass"