Dair
Dair is the Irish name of the seventh letter of the Ogham alphabet, ᚇ, meaning "oak", which is related to Welsh derw(en) and to Breton derv(enn). Its Proto-Indo-European root was *deru- 'oak'. Its phonetic value is [d].
Dair forms the basis of some first names in Irish Gaelic such as Daire, Dara, Darragh and Daragh.