Translation according to P. W. Joyce:
Oltore in Galway; Altoir, an altar. See Altar [reproduced below].
Altar, name of a townland in the neighbourhood of Skibbereen, Cork. The Latin and English word altar was adopted into Irish with its proper meaning to denote a penitential station, with a rude stone altar, where pilgrims pray and perform rounds; exactly like the stations called Ulla, for which see vol. i. p. 339. Many of these altars still remain, and in some cases they mark the spot where open-air Masses were celebrated: see vol. i. p. 120 [reproduced below]. Hence we have Altartate, near Clones in Monaghan, the altar of the tate or land measure.
In "A Tour through Ireland, by two English Gentlemen" (Dublin, 1748), we read:- "The poorer sort of Irish Natives are mostly Roman Catholics, who make no scruple to assemble in the open Fields. As we passed Yesterday in a Bye-road, we saw a Priest under a Tree, with a large Assembly about him, celebrating Mass in his proper Habit; and, though at a great Distance from us, we heard him distinctly. These sort of People, my Lord, seem to be very solemn and sincere in their devotion" (p. 163). The Irish practice of celebrating Mass in the open air appears to be very ancient. It was more general, however, during the period preceding the above tour than at other times, partly because there were in many places no chapels, and partly because, during the operation of the penal laws, the knowledge of this, if we be wise enough to turn it to right account, may have its use, by reminding us of the time in which our lot is cast, when the people have their chape in every parish and those prohibitory enactments are made mere matters of history, by wise and kind legislation. Even in our own day we may witness the celebration of Mass in the open air; for many will remember the vast crowds that congregated on the summit of Brandon hill in Kerry, on the 28th of June, 1868, to honour the memory of St. Brendan. The spots consecrated by the celebration of the sacred mysteries are at this day well known, and greatly revered by the people; and many of them bear names formed from the word Aiffrion (affrin), the Mass, that will identify them to all future time. Places of this kind are found all over Ireland, and many of them have given names to townlands and it may be further observed that the existence of such a name in any particular locality indicates that the custom of celebrating Mass there must have continued for a considerable time. Sometimes the lonely side of a hill was chosen, and the people remember well, and will point out to the visitor, the very spot on which the priest stood, while the crowd of peasants worshipped below. One of these hills is in the parish of Kilmore, county Roscommon, and it has left its name on the townland of Ardanaffrin, the height of the Mass; another in the parish of Donaghmore, county Donegal, called Corraffrin (cor, a round hill); a third in the parish of Kilcommon, Mayo, namely, Drumanaffrin; a fourth in Cavan, Mullanaffrin (mullach, a summit); and still another, Knockanaffrin in Waterford, one of the highest hills of the Cummeragh range. Sometimes, again, the people selected secluded dells and mountain gorges; such as Clashanaffrin in the parish of Desertmore, county of Cork (clash, a trench or fosse), and Lugganaffrin in the county of Galway, the hollow of the Mass. And occasionally they took advantage of the ancient forts of their pagan ancestors, places for ages associated with fairy superstitions; and while they worshipped they were screened from observation by the circumvallations of the old fortress. The old palace of Greenan-Ely near Londonderry was so used; and there is a fort in the townland of Rahanane, parish of Kilcummin in Kerry, which still bears the name of Lissanaffrin, the fort of the Mass. Many other names of like formation are to be met with, such as Glenanaffrin, Carriganaffrin, Lough Anaffrin, etc. Occasionally the name records the simple fact that Mass was celebrated, as we find in a place called Effrinagh, in the parish of Kiltoghert, Leitrim, a name which signifies simply "a place for Mass". And sometimes a translated name occurs of the same class, such as Mass-brook in the parish of Addergoole, Mayo, which is a translation of the Irish Sruthan-an-Aiffrinn. There are other words also, besides Affrin, which are used to commemorate these Masses; such as altóir, an altar, which gives name to a townland, now called Altore, in the parish of Oltore, in the parish of Donaghpatrick, Galway. There is also a place called "Altore cross-roads", near Inchigeelagh, Cork; and we find Carrownaltore (the quarter land of the altar) in the parish of Aglish Mayo.