Quin, Coslett William Charles (1907–95), clergyman and Irish scholar, was born 27 February 1907 at Derriaghy rectory, Co. Antrim, the only son of the Rev. Charles Edward Quin (d. 1936), rector of Derriaghy, and his wife Edith, daughter of Coslett Waddell of Magheralin, Co. Down. He had two younger sisters. He was first educated at Mourne Grange preparatory school, Newry, Co. Down, and later in Campbell College, Belfast, and St Columba's, Dublin. He graduated BA (first moderator) in classics at TCD (1930) and won the vice-chancellor's medal for Latin. He was ordained deacon (1931) and priest (1932) in the Church of Ireland, and was a curate in St Mark's, Dundela, Belfast, from 1931 to 1935. In 1937 he was awarded the degree of BD (Dubl.).
Quin spoke a dozen languages but Irish was his first love, and in the late 1920s he studied local culture and dialects on the Great Blasket Island, Co. Kerry, and on Tory Island, Co. Donegal. From 1936 to 1940 he was curate in Upper Moville, on the Inishowen peninsula, Co. Donegal, where he collected songs, tales, and proverbs in Donegal Irish. He taught classics and Irish at St Columba's College, Dublin, from 1940 to 1942, when he took up a curacy in the diocese of Kilmore, in the parish of Drumlane. He was incumbent of several parishes, in Kilmore and Cork from 1944; while still carrying out parish responsibilities, he was professor (1961–6) of New Testament Greek in TCD. In 1965 he was appointed rector of Dunganstown parish, Co. Wicklow, and prebendary of Swords in St Patrick's cathedral, Dublin (1965–71). He retired in 1971. On top of his full commitment to his parish work, Quin regularly published theological reflections and translations, including The ten commandments (1952) and At the Lord's table (1954), a theological and devotional commentary on the communion service according to the anglican rite of 1662. He contributed reviews to Hermathena, Dublin Magazine, Irish Writing (autumn 1955), and Old Kilkenny Review (1966). A major contribution to Irish scholarship and to Church of Ireland worship was his translation of the Greek New Testament into Irish as Tiomna nua (1970); he similarly translated the Psalms (1965) and the Apocrypha from the Hebrew. His ‘A pragmatic consideration of some Irish traditions’ in Directions: theology in a changing world (1970) developed themes he had explored in ‘W. B. Yeats and Irish tradition’ in Hermathena, xcvii (1963). He also translated theological works by Walter Eichrodt, as well as Rome and Canterbury: a biblical and free catholicism by Amand de Mendieta.
After retiring from active ministry in 1971 Quin began translating the long poem by Brian Merriman (qv), ‘Cúirt an mhean oiche’ (‘The midnight court’), which he completed in July 1979 and published in 1982. In 1990 he published Scian a caihleadh, a collection of songs and stories from the Inishowen and Erris Gaeltachts. On 5 December 1994 Quin's Irish manuscripts were presented to the RIA. The thirty notebooks contained songs, stories, proverbs, word-lists, and Quin's thoughts on the state of Irish in the Co. Donegal and Co. Kerry Gaeltachts and in Co. Antrim and Co. Armagh. After a short illness, he died 6 December 1995 at the Adelaide Hospital, Dublin, and was buried in Dunganstown churchyard, Co. Wicklow.
On 19 February 1944, while a curate in Kilmore, Quin married Theodore (‘Doreen’), daughter of the Rev. John Jennings, incumbent of a nearby parish, Kildallon. He shared his wife's interest in the welfare of prisoners in Irish jails. They had two sons and a daughter.