Translation according to P. W. Joyce:
Knocknahaw in Galway; Cnoc-na-haithche, hill of the (lime) Mln. See Aith, vol. i. p. 377 [reproduced below].
Aith [ah] denotes a kiln of any kind, whether a lime-kiln or a kiln for drying corn. It is generally found in the end of names, joined with na, the gen. fem. of the article, followed by h, by which it is distinguished from ath, a ford, which takes an in the genitive. There are several places in Monaghan and Armagh, called Annahaia and Annahagh, all of which are from the Irish, Ath-na-haithe, the ford of the kiln; we find Ballynahaha in Limerick, and Ballynahaia in Cavan (Bally, a town); in Antrim, Lisnahay (Lis, a fort); Gortnahey in Londonderry, Gortnahaha in Clare and Tipperary, and Aughnahoy in Antrim, all of which signify the field of the kiln.