A crash course in Gaelic pronounciation:

Niall na Naoi nGiallaibh, Neil of the Nine Hostages, is pronounced (idiot phonetics):

NyEE-al nuh NuEE NGEE-al-av

(approximately, and in Munster dialect!)

Thus it contains at least 3 (possibly 4) distinct n sounds, completely unfamiliar to native English speakers, unless they have experience of Russian or Arabic, for exmaple!

I recommend you pronounce this phrase several times until you feel you have mastered the four distinct sounds. At the end of that I think you'll find yourself laughing spontaneously. This sort of tongue twister is common in ancient Irish literature, something that to me suggests that the title of this semi-legendary figure may have been modified to form a mnemonic rather than accurately describe his achievements.

The "hostages" (Giallaibh) refer to the nine territories/tribes that Niall is credited with subjugating (including parts of Britain and Gaul).

By the way, the Gaelic form of Mahon, Mathghumhain or Mathuin/Mahuin in modernised spelling, is pronounced mah-KHOO-wine or (simplified) ma-HOO-in.

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