the corner, nook (pasture?) of —
The meaning of Doirnín is uncertain.

While this place-name is not particularly well attested in the usual sixteenth and seventeenth-century sources the historical forms collected demonstrate that it is clearly an abbreviated form of anglicised ‘Cooldurneen’ or similar, which was still in use in the nineteenth century. In regard to the underlying Irish form of this ‘Cooldurneen’ the overall evidence is broadly in keeping with derivation from ‘Cúil Duirnín’ as suggested by John O’Donovan during the course of the Ordnance Survey in 1836, and he may well have heard this version himself locally. This can be standardised as Cúil Doirnín (cf. Derrydorneen/Doire Doirnín (ME); Carrowdurneen/Ceathrú Uí Dhoirnín (Sl)).

Anglicised toponyms containing Cool-, Col-, Cul-, etc., are generally considered to be derived from either cúl “back” or cúil “corner, angle, recess, nook”. The evidence provided by anglicised forms rarely suffices to distinguish between these generic elements, essentially due to the tendency for palatal consonants not to be reflected in anglicisation (cf. The Origin and History of Irish Names of Places I, Joyce, P.W., pp. 530–1; Irish Place Names, Flanagan D. & Flanagan L., 1994 pp.65‒6). However, it has been demonstrated that very few unambiguous examples of place-names containing cúl occur in early Irish sources, in contrast to the frequent occurrence of cúil (see ‘The Backward Nook: Cúil and Cúl in Irish Place-Names’, Toner, G., in Ainm 7, pp.113–7). Therefore the anglicised elements Cool-, Col-, etc., are best considered to derive from cúil unless the evidence, either linguistic or topographic, is clearly to the contrary. (Note that the alternation of cúil and cúl found in attested Irish examples of certain place-names is probably due to scribal inconsistency rather than confusion in the spoken forms of the names: e.g. ‘go Cúil Raithin’ vs. ‘go Cúl Raithin’ [Coleraine, Do]; ‘fríd ... Cúil Áine’ vs. ‘go Cúl Áine’ [Coolaney, Sl]; ‘Cúil Caissine’ vs. ‘Cul Caissine’ [Coolcashin, CC]; see Corpas na Gaeilge.)

Cúil is usually explained as “corner, recess, nook”. However, the anglicised element cloon, clon, etc. (< cluain), at times appears in the historical evidence for place-names where anglicised cool (< cúil) is expected, and vice versa, and it is conceivable that there may have been some crossover between the meaning of cúil and cluain in some parts of the country. As a result, the term “pasture?” may possibly be added to the explanation of cúil here (see Logainmneacha na hÉireann IV: The Townland Names of Co. Wexford, p.172, Ballinacoola). Indeed, it is interesting to note that some historical forms of Coole such as ‘Clondernan’ actually reflect an initial cluain, although it is uncertain as to the reliability of such evidence in this instance.

The meaning the final element of Cúil Doirnín is not absolutely clear. John O’Donovan in his explanation of the name, “Duirnins [Doirnín’s] corner or angle”, suggests that he understood it to be a personal name. This is quite reasonable give the existence of the surname Ó Doirnín (see: Sloinnte Gaedhal is Gall, Woulfe, P.W. (1923), Ó Doirnín, Ó Duirnín), as found in the Sligo place-name Carrowdurneen/Ceathrú Uí Dhoirnín (see logainm.ie #44972), and the fact that most native Irish surnames are based on the construction of Ó (later mac) + personal name. However, such a personal name does not appear to have been at all common among the Irish, and it therefore seems likely that Ó Doirnín was actually based on a nickname such as Doirnín “little fist”. Cúil Doirnín might then be explained as meaning “(the) corner, angle, recess, nook (pasture?) of Doirnín (nick-name)”. That said, Fiachra Mac Gabhann points out in his note on the place-name Derrydorneen/Doire Dhoirnín in Mayo that doirnín is also attested in a topographical sense, in reference to a sand-bank at Corraun/An Corrán, which may be a development from doirnín “projecting handle of scythe” (see: Logainmneacha Mhaigh Eo; anailís ar ainmneacha na mbailte fearainn agus roinnt ainmneacha eile i mBarúntacht Choistealach in oirthear Mhaigh Eo, Mac Gabhann, Fiachra (2014). Indeed, the common noun doirnín is also found as the qualifier in the place-name Ballaghaderneen/Bealach an Doirnín “pass of (at the feature similar to) the little fist, projecting handle of a scythe” in Carlow, although the feature in question is now unknown. There may, then, be or have been some feature in the area of Cúil Doirnín that also generated such a comparison.
[Dr. Conchubhar Ó Crualaoich]