Dinneen, Patrick Stephen (Ó Duinnín, Pádraig Stiabhna ) (1860–1934), Irish language lexicographer, was born 25 December 1860 on a smallholding in Carn townland near Rathmore in the Sliabh Luachra district of Co. Kerry, fifth of ten children of Maitiú Ó Duinnín, farmer and livestock trader, and Máire Ní Dhonnchadha (d. 1917). His parents, who had been evicted from a more substantial farm a few years previously, were native Irish-speakers. Although Pádraig was brought up largely through English, Irish was still very much in evidence during his childhood, and he first heard many of the poems of local poet Aogán Ó Rathaille (qv) from his mother. He received his earliest formal education in the local national school and later (at the age of 10) in the national school at Na Míteoga, from his uncle. His ability was obvious from an early age and he became a monitor in that school in 1874. He left aged 17 and stayed at home for three years, taking Latin lessons from the parish priest of Rathmore, presumably with a view to entering the priesthood. His mother's excessive piety must have been a factor in his choice of calling. Under the influence of Denis Murphy (qv), SJ, he joined the Jesuits in September 1880. He was ordained in 1894, but his training lasted until summer 1898. He completed his years in formation (1880–82) and as a scholastic (1891–5) at Milltown Park, Dublin, and his tertianship in Tronchiennes, Belgium (1897–8). In 1883–5 he studied mathematics and modern literature in UCD – under Gerard Manley Hopkins (qv) and Seán Ó Cathasaigh among others – graduating with an honours BA. His forte was mathematics, in which he received an MA (1889). All other years of his training were spent teaching – three of them as an assistant in mathematics in UCD (1885–8), and the rest in Jesuit novitiates and schools. After completing his training, he taught in Clongowes Wood, Co. Kildare, for two years. Although much folklore surrounds his (regular and fairly amicable) parting of ways with the Jesuits (1900), it would seem that he left because his superiors thought him unsuitable for life in the society – toisc é a bheith beagainín corr ann féin (‘because he was a little bit eccentric’), as one Jesuit put it. He wore clerical garb until his death, and was allowed to continue presenting himself as a priest, but not to administer the sacraments without first being licensed to do so by a bishop. He was later offered such permission by the archbishop of Dublin, but failed to take it up because this would involve showing private documentation to prove that he could support himself independently – and he was always intensely private about his personal affairs. This did not, however, stop him from accepting offerings to hear mass for people's intentions. There is little evidence that he showed any interest in Irish before 1899, when he began teaching it in Clongowes and also made a submission in support of the language to a government commission on education. His conversion may have come about under the influence of his friend and fellow Jesuit, the Irish scholar Fr John MacErlean (qv). He soon plunged headlong into Irish scholarship and quickly established himself as a leading authority on Irish literature. By 1906, he had produced fairly reliable editions of the poetry of many of the most important Munster poets: Aogán Ó Rathaille, Eoghan Rua Ó Súilleabháin (qv), Seán Clárach Mac Domhnaill (qv), Séafraidh Ó Donnchadha an Ghleanna (qv), Tadhg Gaelach Ó Súilleabháin (qv), Piaras Feiritéar (qv), and the Maigue poets. He also edited Faoistin Naomh-Phádraig, the eighteenth-century prose text Me Guidhir Fhearmanach, and three of the four volumes of the highly valuable Foras feasa ar Éirinn by Seathrún Céitinn (qv). He published these through Conradh na Gaeilge's publications' committee and through the London-based Irish Texts Society (ITS). The latter also printed his pioneering Irish–English dictionary, which was widely welcomed when it came out in 1904. Although he later claimed that most of this dictionary was compiled from material ‘stored up in my childhood's memory’, in fact it drew heavily on published literature, on unpublished lexicons, and on manuscript sources, as well as on word lists submitted from the various Gaeltacht areas. When the plates for this publication were destroyed during the 1916 rising, he embarked with the assistance of Liam S. Gógan (qv) on a second, much expanded edition, which appeared in 1927 and was the standard Irish–English dictionary until 1977 (when it was largely replaced by Niall Ó Dónaill's (qv) Foclóir Gaeilge-Béarla). The 1927 edition and its predecessor made a significant contribution to the standardisation of Irish orthography. It has been widely consulted since 1977 – particularly by readers of material published before the advent of today's official standard Irish and by those wishing to access its considerable body of proverbs and idiomatic expressions. This is the dictionary that ‘Myles na Gopaleen’ (Flann O'Brien (qv)), poked fun at for years in his ‘Cruiskeen Lawn’ column in the Irish Times, christening Ó Duinnín ‘our great comic lexicographer’.
In contrast to his lexicographical work, Ó Duinnín's literary attempts (including a novel, some plays, and several poems) are less than memorable. However, his novel Cormac Ó Conaill (1901) is of no small historical importance: it was the first novel of the literary renaissance. As well as being a member of the Society for the Preservation of the Irish Language, and of the ITS, Ó Duinnín was an active member (1900–09) of Conradh na Gaeilge: he sat on many of its most influential committees, including its Coiste Gnó – where, according to Piaras Béaslaí (qv), he was usually in a ‘magnificent minority of one’. His main platform within the Conradh was the Munster-leaning and pro-catholic Craobh an Chéitinnigh, of which he was made president (1904). This branch operated as an independent republic within the Conradh, and was more often than not at loggerheads with the leadership. From there, he played an active part in the virtual civil war that bedevilled the language movement in the early years of the twentieth century. He came under the influence of his friend D. P. Moran (qv), and wrote a column in the latter's Leader (1906–29), using this and the letter columns of other newspapers to assail the Conradh's leaders, particularly Douglas Hyde (qv) and P. H. Pearse (qv). He thought the latter pretentious, and often referred to him with mock seriousness as ‘Pee Haitch’ and ‘BABL’. In 1906, in a celebrated letter purporting to be from a person by the name of Snag Breac (‘Magpie’) to the Irish People newspaper, he criticised a novel that Pearse had recently published under the pseudonym ‘Colm Ó Conaire’ (supposedly a western writer), saying it ‘smacks more like the margarine of the slums than pure mountain butter’. He also poked fun at the innocent Pearse's choice of title, Poll an phíobaire (‘The piper's hole’), expressing the hope that ‘the Píobaire will continue to draw from the stores of his capacious and well-filled arsenal’! From 1909 until his death Ó Duinnín devoted himself exclusively to his studies. Although he was awarded (1920) an honorary D.Litt. in absentia by the NUI, he never had much contact with the academic establishment. For many years, he was a permanent fixture in the National Library (where he receives mention in Joyce's (qv) Ulysses) and in the RIA library, where he spent the winters. He was a well known and well liked character around Dublin in the early decades of the century. He cut a rather colourful figure in his tall hat and shabby coat (which he once borrowed from a friend but neglected to return), and was remembered by many not because of his great dictionary but because of his mild eccentricity: his habit of talking to himself and chewing dulse in the library, his awful puns (‘O'Neill-Lane? Ó, níl aon mhaith ann’), or his legendary miserliness (which once led him to enter a children's writing competition and pocket the prize). He died Saturday 29 September 1934 and, after funeral Mass in the Jesuits' Gardiner St. church, was buried in Glasnevin cemetery.