Trans. Whitley Stokes
Ulaid, whence where they named? Easy (to say). Ulaid, that is, oll saith, that is, great (oll) wealth (saith) which they gave the poets. Saith means 'wealth', and (here is) an example of this, as saith the Amra (Choluimchille) :
On a Wednesday Judas transgressed (his) order
In the Devil's track, a fierce revenge:
On a Wednesday he felt desire for wealth:
On a Wednesday he betrayed noble Jesus.
Or Ulaid, that is, they have the great (oll) half (leth) of Ireland, as regards warfare and battle.
Or Ulaid, that is, "great-gray", that is, they had gray beards in the battle of Oenach Macha, i.e. they tied gray wool to their chins in the same battle, that is, in the battle they had grey beards.
Conchobar, son of Fachtna Fathach, and his brethren, 'tis they that fought the battle of Oenach Macha with Daball of the Vehement Blows, son of the overking of Lochlann. Innumerable, now, was the army that was then along with the king of Lochlann's son, invading the province of Ulster in order to conquer Ireland. There they first encamped, and they afterwards marched on to Mag Macha.
The clans of Rudraige gathered round Conchobar against the foreigners, to deliver battle to them. Then said Genann Bright-cheek, son of Cathbad, to his people: "Scanty are your hosts, ye Ulaid!" quoth he, "and each of you is young and beardless". "What shall we do therefore, Genann?" says every one. "Do this, ye warriors", quoth Genann. "Take plenty of gray wool, and tie the wool fast to your faces, and thence the horror and fear of the foreigners will be the greater, as if ye were kingly champions". So the Ulaid — at least all who were beardless — acted on Genann's advice. Then the battle was fought, and the foreigners were routed, and their slaughter was inflicted therein. Wherefore from that battle of Oenach Macha the Ulaid were (so) called, as the poet said:
Fachtna's clans, no fault have they
Against every *** of battle ***
From them are named ***
The Ulaid, since they were gray-bearded, mighty.
Or Ulaid, from Ollam Fodla, son of Fiacha Finscothach .i.e. Ulaid, a great spreading (oll-lethad) of 0llam, that is, greatly did the Ulaid spread and descend from Ollam Fodla. Or Ulaid, i.e. oll ai ollam is said in another place. For he was a wonderful poet, and therefore is he called Ollam Fodla, and from him the Ulaid are veritably called, as, for example:
Ollam Fodla ***
From him the Ulaid were named.
The feast of Tara of the households truly
By him (as) leader was ordained.
Sources : Whitley Stokes, Irische Texte 3