Flann O’Brien’s The Poor Mouth is titled An Béal Bocht nó An Milleánach in the original Irish (and “edited” by Myles na gCopaleen). As noted in a recent Irish Times article about it by Mairin Nic Eoin, an milleánach means “the fault-finding one or the one from the land of fault-finding”.
Milleánach is the adjective form of the noun milleán, blame: i.e., blameful or censorious. In Patrick Dinneen’s 1904 Irish-English dictionary, milleánach is defined as “blaming, rebuking”. In the shorter 1938 edition for schools, it is defined as “blaming, finding fauth with”.
Technically, I think, it should be in the genitive masculine form, milleánaigh, because it describes an béal, which is masculine. But also technically, its use in the title is as a noun, which it isn’t. The solution is to imply the subject, i.e., “The Censorious [One/Thing]”, or follow the analogy of oileán (island) to oileánach (islander) to come up with the nonsensical “one who lives in (to?) blame”. Why not simply “The Censor”? Or perhaps, on the analogy of iasc and iascach (fish and fishing), “The Blaming”?
What is clear, however, as also noted by Nic Eoin, is that Brian Ó Nualláin’s primary intention was to echo the title of Tomás Ó Criothann’s classic memoir of life on The Great Blasket, An tOileánach.
My Irish teacher (who earned her certificate around the same time that An Béal Bocht was written) thought that An Milleánach meant The Millionaire (an milliúnaí in modern Irish; no entry in either Dinneen). That certainly makes more sense as an ironic comment on the main title instead of mere word play.
And in fact the hero of An Béal Bocht does venture to Cruach an Ocrais and takes the horde of the legendary Maoldún Ó Pónasa, the lone survivor of the Deluge of Corca Dhorca, which he buries for himself (after fleeing the corpse’s reanimation into all-too-familiar storytelling).
Furthermore, na Gopaleen wrote in his “Cruiskeen Lawn” column in The Irish Times (as reprinted in The Best of Myles (New York: Walker, 1968; reprinted by Dalkey Archive Press [Normal, Illinois], 1999), “A lady lecturing recently on the Irish language drew attention to the fact … that, while the average English speaker gets along with a mere 400 words, the Irish-speaking peasant uses 4,000. … The 400/4,000 ration is fallacious; 400/400,000 would be more like it. There is scarcely a single word in the Irish (barring, possibly, Sasanach) that is simple and explicit. … In Donegal there are native speakers who know so many million words that it is a matter of pride with them never to use the same word twice in a life-time.”
Ó Criomhthain himself, whom na Gopaleen particularly praises, cherished that language given to him by his parents. For example, after his mother dies, joining his father, he writes:
Sin críoch leis an mbeirt do chuir sioladh na teangan so im’ chluasa an chéad lá. Beannacht Dé le n-a n-anam. (That was the end of the two who [from the first day] put the sound of this language of ours in my ears. May the blessing of God be on their souls. [Translation by Garry Bannister and David Sowby.])
One might also consider the suggestion of milleanna, bell flowers, and millteanach, terrible. Not to mention meilleanna, grimaces (poor mouths!).