The pre-Christian gods who invaded and inhabited Ireland, sometimes represented as heroes or fairies. They were defeated by the Milesians and driven underground.
Origin of tuatha-de-danaan
- Middle Irish Túatha Dé Danann (traditionally interpreted as meaning “Tribes of the goddess Danu”) from Old Irish Túatha Dé Donann tuatha pl. of túath people, tribe dé genitive of día god, goddess Donann of unknown origin
From American Heritage Dictionary of the English Language, 5th Edition