Line 3 of the above stanza seems to be baithium riam reim for bra, taking reim from the Egerton text.  The allusion is to a cascade.

When the noble Naisi spread out a cooking-hearth on hero-board of tree, sweeter than any food dressed under honey[FN#69] was what was captured by the son of Usnach.

[FN#69] For “food dressed under honey” compare Fraech, line 544, in the second volume.

Though melodious to you each month (are the) pipers and horn-blowers, it is my open statement to you to-day I have heard melody sweeter far than these.

For Conor, the king, is melody pipers and blowers of horns, more melodious to me, renowned, enchanting the voice given out by the sons of Usnach.

Like the sound of the wave the voice of Naisi, it was a melodious sound, one to hearken to for ever, Ardan was a good barytone, the tenor of Aindle rang through the dwelling-place.

Naisi is laid in his tomb, sad was the protection that he got; the nation by which he was reared poured out the cup of poison by which he died.

Dear is Berthan, beautiful its lands, stately the men, though hilly the land, it is sorrowful that to-day I rise not to await the sons of Usnach.

Dear the mind, firm, upright, dear the youth, lofty, modest, after going with him through the dark wood dear the girding (?) at early morning.

Dear his gray eye, which women loved, it was evil-looking against enemies, after circuit of the wood (was) a noble assembly, dear the tenor through the dark wood.

I sleep not therefor, and I stain not my nails with red, joy comes not to my wakefulness, for the sons of Usnach return not.

The last line is the Egerton reading.

I sleep not for half the night on my bed, my mind wanders amidst clouds of thoughts, I eat not, nor smile.

There is no leisure or joy for me in the assemblies of eastern Emain; there is no peace, nor pleasure, nor repose in beholding fine houses or splendid ornaments.

What, O Conor, of thee? for me only sorrow under lamentation hast thou prepared, such will be my life so long as it remains to me, thy love for me will not last.

The man who under heaven was fairest to me, the man who was so dear thou hast torn from me; great was the crime; so that I shall not see him until I die.

His absence is the cause of grief to me, the shape of the son of Usnach shows itself to me, a dark hill is above his white body which was desired before many things by me.

His ruddy cheeks, more beautiful than meadows (?), red lips, eyebrows of the colour of the chafer, his teeth shining like pearls, like noble colour of snow.

Well have I known his splendid garb among the warrior men of Alba; mantle of crimson, meet for an assembly, with a border of red gold.

His tunic of satin of costly price, on it a hundred pearls could be counted, goodly the number (lit. “a smooth number” ? a round number), for its embroidery had been used, it was bright, fifty ounces of findruine (i.e. white bronze).