Translation according to P. W. Joyce
Clogh stands for cloch, a stone, or a stone castle. See vol. i. p. 411 [reproduced below].
Cloch signifies a stone - any stone either large or small, as, for instance, clock-shneachta, a hail-stone, literally snow-stone; cloch-teine, fire-stone, i.e. a flint. So far as it is perpetuated in local names, it was applied in each particular case to a stone sufficiently large and conspicuously placed to attract general notice, or rendered remarkable by some custom or historical occurrence. This word is also, in an extended sense, often applied to a stone building, such as a castle; for example, the castle of Glin on the Shannon in Limerick, the seat of the Knight of Glin, is called in Irish documents Cloch-gleanna, the stone castle of the glen or valley. It is often difficult to determine with certainty which of these two meanings it bears in local names. Cloch is one of the our commonest topographical roots; in the English forms Clogh and Clough, it constitutes or begins more than 400 townland names; and it helps to form innumerable others in various combinations. Cloghbally and Cloghvally, which are common townland names, represent the Irish Cloch-bhaile, stony-town; scattered over Munster, Connaught, and Ulster, are many places called Cloghboley and Cloghboola, stony booley or dairy-place; and Cloghvoley, Cloghvoolia, and Cloghvoula, are varied forms of the same name; Shanaclogh and Shanclogh in Munster and Connaught, old sone or stone castle. Sometimes the final guttural drops out and the word is reduced to clo; as in Clomantagh in Kilkenny, in which no guttural appears, though there is one in the original Cloch-Mantaigh, the stone or stone-castle of Mantach, a man's name signifying toothless (see p. 109), said to have taken its name from a stone circle on the hill; Clonmoney and Clonrusk in Carlow, the former signifying the stone of the shrubbery, and the latter, of the rusk or marsh. And very often the first c becomes g by eclipsis (see p. 22), as in Carrownaglogh, which conveys the sound of Ceathramhadh-na-gclogh (Book of Lecan), the quarter-land of the stones. Names formed from this word, variously combined, are found in every part of Ireland: when it comes in as a termination, it is usually in the genitive (cloiche, pron. Clohy), and in this case it takes several modern forms, which will be illustrated in the following names: - Ballyclogh, Ballyclohy, Ballinaclogh, Ballynaclogh, and Ballynacloghy, all names of frequent occurrence, mean stone town, or the town of the stones. Kilnacloghy, in the parish of Cloontuskert, in Roscommon, is called Coill-na-cloiche in the Four Masters, the wood of the stone. Aughnacloy is a little town in Tyrone; and there are several townlands in other counties of the same name, all called in Irish Achadh-na-cloiche [Ahanaclohy], the field of the stone. There are three diminutives of this word in common use - cloichin, clochóg, and cloghán - of which the third has been already dealt with (p. 363). The first is generally anglicised Cloheen or Clogheen, which is the name of a town in Tipperary, and of several townlands in Cork, Waterford, and Kildare. Cloghoge or Clohoge, though literally meaning a small stone like Clogheen, is generally applied to stony land, or to a place full of round stones; it is the name of about twenty townlands, chiefly in Ulster - a few, however, being found in Sligo and in the Leinster counties. There are several derivative forms from this word cloch. The most common is clochar, which is generally applied to stony land - a place abounding in stones, or having a stony surface; but it occasionally means a rock. Its most usual anglicised form is Clogher, which is the name of a well-known town in Tyrone, of a village, and a remarkable headland in Louth, and of nearly sixty townlands scattered over Ireland; and compounded with various words, it helps to form the names of numerous other places. For Clogher in Tyrone, however, a different origin has been assigned. It is stated that there existed anciently at this place a stone covered with gold, which was worshipped as Kermann Kelstach, the principal idol of the northern Irish; and this stone, it is said, was preserved in the church of Clogher down to a late period: hence the place was called Cloch-oir, golden stone. O'Flaherty makes this statement in his Ogygia, on the authority of Cathal Maguire, Archdeacon of Clogher, the compiler of the annals of Ulster, who died in 1495; and Harris in his edition of Ware's Bishops, notices the idol in the following words: - "Clogher, situated on the river Lanny, takes its name from a Golden Stone, from which, in the Times of Paganism, the Devil used to pronounce juggling answers, like the Oracles of Apollo Pythius, as is said in the Register of Clogher". With this story of the idol I have nothing to do; only I shall observe that it ought to be received with caution, as it is not found in any ancient authority; it is likely that Maguire's statement is a mere record of the oral tradition, preserved in his time. But that the name of Clogher is derived from it - i.e. from Cloch-oir - I do not believe, and for these reasons. The prevalence of the name Clogher in different parts of Ireland, with the same general meaning, "is rather damaging to such an etymon", as Dr. Reeves remarks, and affords strong presumption that this Clogher is the same as all the rest. The most ancient form of the name, as found in Adamnan, is Clochar Filiorum Daimeni (this being Adamnan's translation of the proper Irish name, Clochur-mac-Daimhin, Clochur of the sons of Daimhin); in which the final syllable ur shows no trace of the genitive of ór, gold (ór, gen óir); and, besides, the manner in which Clochur is connected with mac-Daimhin goes far to show that it is a generic term, the construction being exactly analogous to Inis-mac-Nessan (p. 109). But farther, there is a direct statement of the origin of the name in a passage of the Tain-bo-Chuailgne in Leabhar na hUidhre, quoted by Mr. J. O'Beirne Crowe in an article in the Kilkenny Archaeological Journal (April, 1869, p. 311). In this passage we are told that a certain place on which was a great quantity of stones, was called for that reason Mag Clochair, the plain of the stones; and Mr. Crowe remarks: - "Clochar, as any Irish scholar might know, does not mean a stone of gold; the form form clochar from cloch, a stone is like that of sruthar from sruth, a stream, and other nouns of this class with a cumulative signification". This place retains its ancient name in the lates Irish authorities. Daimhin, whose sons are commemorated in the name, was eighth in descent from Colla-da-Chrich (p. 137), and lived in the sixth century. His descendants were in latter times called Clann-Daimhin [Clann Davin]; and they were represented so late as the fourteenth century, by the family of Dwyer. Cloghereen, little stony place, a diminutive of clogher, is well known to tourists as the name of a village near Killarney. Cloichreán, or cloithreán [cloherawn], another diminutive, signifies also a stony place, and is found in every part of Ireland in different modern forms. It is Cloghrane in Kerry and Waterford; and in the county of Dublin it gives name to two parishes called Cloghran. In many cases the guttural has dropped out, reducing it to Cloran in Westmeath, Tipperary, and Galway; Clorane and Clorhane in Limerick, King's and Queen's County. It undergoes various other alterations - as for instance, Clerran in Monaghan: Cleighran in Leitrim; Cleraun in Longford; and Clerhaun in Mayo and Galway. Clochar has other developments, one of which, cloharach or cloithreach, meaning much the same as clochar itself - a stony place - is found pretty widely spread in various modern forms; such as Cloghera in Clare and Kerry; and Clerragh in Roscommon. Another offshoot is cloichearnach with still the same meaning; this is anglicised Cloghernagh in Donegal and Monaghan; Clahernagh in Fermanagh; Clohernagh in Wicklow and Tipperary; while in Tyrone it gives the name of Clogherny to a parish and four townlands.