Translation according to P. W. Joyce:
Derryinver in Armagh and Galway; of the river-mouth. See Inbhear, vol. i. p. 459 [reproduced below].
Inbhear [inver], old Irish inbir (Cor. G1.), means the mouth of a river; "a bay into which a river runs, or a long narrow neck of the sea, resembling a river" (Dr. Todd). The word is pretty common in Ireland, and equally so in Scotland, generally in the form of inver, but it is occasionally obscured by modern contraction. At A.D. 639, the Four Masters record the death of St. Dagan of Inbhear-Daeile [Invereela], i.e. the mouth of the river Deel; this place, which lies in Wicklow, four miles north from Arklow, retains the old name, modernised to Ennereilly, though the river is no longer called the Deel, but the Pennycomequick. The townland of Dromineer in Tipperary, which gives name to a parish, is situated where the Nenagh river enters Lough Derg; and hence it is called in Irish Druim-inbhir, the ridge of the river-mouth.