A nymph is defined as "one of a class of semi-divine beings, imagined as beautiful maidens inhabiting the sea, rivers, fountains, hills, wood, or trees, or attending on superior deities".

The Shorter Oxford Dictionary lists this as early as 1584. In a poetical sense it meant "a young and beautiful woman; hence a maiden, damsel". Nymphhall names a townland in the Waterford parish of Killea, situated not far from the coastal town of Dunmore East. We can only surmise that this was once the name of some no-longer extant residence. We take it that this was what PW Joyce in his Irish Names of Places called "a fancy name". The original and older Irish name for this place was Gleann Díomais "the valley of the pride or arrogance". This had been anglicised Glandemus in the 1654 Civil Survey, though no form of it exists any longer. Canon Power's The Place-Names of Decies does not list Nymph Hall in the Index, though it is mentioned as being in the townland of Dunmore. "Under the head of Dunmore is to be included Nymph Hall, a portion of Dunmore cut off to form a separate townland with the foregoing fancy name." Some time in the late 1700s it was noted that one John Rogers had fished "off the Nymph Bank" though we have not located it on our Ordnance Survey map. The Nymph Fishing Bank was said to have "stretched from Dungarvan to Cape Clear".

Killea names places in counties Cavan, Leitrim, Limerick, Derry, Roscommon, Tipperary (5) and Waterford. The last listed is given in Canon Power's The Place-Names of Decies as deriving from Cill Aodha "Aodh's church", as probably do the others.