What is "tathana"

Saint Tathana was a 5th-century Pre-congregational saint of South Wales. Very little is known of her actual life. She was born c.465 AD and she was the granddaughter of Meuric ap Tewdric of Trebeferad. She who lived a humble life as a nun in a mud hut on the River Thaw, and was associated with the monastic school of Llantwit Major where she was buried.