Wiktionary
n. (context Irish mythology English) The daughter of Scáthach and later the lover of Cúchulainn (after a duel with Cochar Crufe).
Wikipedia
In Irish and Scottish mythology, Uathach was Scáthach's daughter and thus the niece of her rival and sister Aífe. Cú Chulainn, who had recently arrived at Scáthach's fortress-home Dún Scáith (Fortress of Shadows) to be her pupil, accidentally broke one of Uathach's fingers, and Uathach's suitor, Cochar Croibhe, challenged him to single combat despite Uathach's protests. Cú Chulainn killed him and became Uathach's lover.
Usage examples of "uathach".
In careful silence he had observed as Uathach, the giant urgach in white, had enforced an orderly withdrawal out of what had begun as blind flight.
Gradually through the greyness of dawn he had let the army pass him by, making sure that Uathach did not notice.
Six months ago Uathach had been summoned to Starkadh, an oversized urgach, as stupid as any of the others, a little more dangerous because of quickness and size.
He turned, his heart lurching, and looked north, along the downward-sloping path to where Uathach waited on the stony plain.
Because he remembered Uathach too, from the bloody banks of the Adein in the first battle of Kevin’s spring.
Dave knew how desperately Levon had wanted the death of this creature, and how adamant Tore—who feared nothing else that Dave knew—had been in binding Levon by oath not to fight Uathach alone.
Taking Uathach unto himself, that Arthur and Lancelot, both, might go forward past this day.
At the descent of dark, through a blurring mist of tears, she saw him take his wound, saw him kill Uathach, saw the beautiful, rearing horse gored hideously from below by the ripping horn of the slaug.
More dangerous than even Uathach would have been, more subtle in his malice.
Then you thought to find your ending in battle with Uathach, and you did not.
They had got their skill in arms, and valour, and bravery from the same teachers, from Scáthach, from Uathach, and from Aife[1].
For when we were with Scáthach, with Uathach, and with Aife, thou wert mine attendant.
It is because that when with Scáthach, with Uathach, and with Aife we abode, it was the custom with us that together we should go to every battle, and to every field of battle.
And that day he displayed noble, many-changing, wonderful, and many feats that he had learned from none: neither from Scáthach, from Uathach, or from Aife.