Translation according to P. W. Joyce:
Barraderra, Barraderry in Kildare, Galway, Wicklow; summit of the derry or oakwood. (Derry, vol. i. p. 503.)
Doire or daire [derry] is an oak-wood, and is almost always represented in anglicised names by derry or derri. Derrylahan, a very usual name, signifies broad oak-wood; the wood still remains on the side of a hill at Glendalough in Wicklow, that gave it the name of Derrybawn (bán, whitish), and this is alsothe name of other places; Derrykeighan, a parish in Antrim, is called in Irish, Dorie-Chaechain (Four Mast.), Caechan's or Keeghan's grove. When doire is joined with the gen. mas. of the article, it becomes in English derrin, which begins many names. Thus Derrinlaur, a townland in which are the ruins of a castle, in Waterford, not far from Clonmel, is mentioned by the Four Masters, who write the name Dorie-an-lair, middle derry. And sometimes it is contracted to der, as in Dernagree in Cork, the same as Derrynagree in other places, the wood of the cattle; Derradd in Westmeath, and Derrada in the Connaught counties, which are the same as Derryadd in the middle and north of Ireland, Derryadda in Mayo, and Derryfadda in the south and west - all from Doire-fhada, long oak wood, the f being aspirated and omitted in some.