Irish genealogy speaks three languages at once — administrative English, register Latin, and anglicised Irish — and half of every beginner’s confusion is vocabulary. This glossary translates the lot.
Bookmark it, and come back whenever a record says something strange. Terms are grouped by where you will meet them.
Geography and Land Divisions
- Townland: Ireland’s smallest official land division (~61,000 of them) — the rural address on nearly every record, and the most valuable fact in your research.
- Civil parish: the administrative parish used by surveys and records — distinct from, and imperfectly aligned with, the Catholic parish.
- Catholic parish: the Church’s unit — the geography of the parish registers; one Catholic parish may span several civil parishes, under a different name.
- Barony: an obsolete division between parish and county — survives as a search filter in Griffith’s and older sources.
- Poor Law Union (PLU): the workhouse-centred districts that became the civil registration districts — why your ancestor “registered in” a town the family never lived in.
- District Electoral Division (DED): census-era subdivision — the browse path through the 1901/1911 returns.
Records and Institutions
- GRO / GRONI: the General Register Offices — Dublin for the Republic (and the all-island historic registers), Belfast for post-1922 Northern Ireland.
- Civil registration: State recording of births, marriages, deaths — island-wide from 1864; non-Catholic marriages from 1845.
- Long-form certificate: the full certified copy naming parents — the only grade citizenship applications accept; short-form extracts omit the genealogy.
- FBR — Foreign Births Register: the register through which the diaspora claims citizenship by descent — the application guide.
- Griffith’s Valuation: the 1847–1864 property survey serving as the census substitute; Tithe Applotment Books are its thinner 1820s–30s predecessor.
- Revision / cancelled books: the Valuation Office volumes tracking every later change of occupier — Griffith’s, continued.
- PROI / the 1922 fire: the Public Record Office of Ireland, burned at the Civil War’s outbreak — what was lost and what survived.
- Virtual Record Treasury: the modern digital reconstruction of the burned archive — free, and growing.
Latin in the Parish Registers
- Baptisavi: “I baptised” — opens most baptism entries.
- Filius / filia legitimus(-a): lawful son / daughter; illegitimus(-a) records birth outside marriage.
- Sponsores (or patrini): the godparents — overwhelmingly drawn from the two families, and the register’s gift to kin-reconstruction.
- In matrimonium conjunxi: “I joined in marriage”; testes are the witnesses.
- Dispensatio (in tertio gradu, etc.): a consanguinity dispensation — bride and groom already related in the stated degree; third degree ≈ second cousins.
- Common Latinised forenames: Patritius/Patrick, Joannes/John, Gulielmus/William, Jacobus/James, Maria/Mary, Brigida/Bridget, Honoria/Hanora(Nora), Margarita/Margaret.
- The full reading method: the parish registers guide.
Names and Naming
- Ó / O’: “descendant of”; Mac / Mc: “son of” — the Gaelic patronymics, decoded in the prefixes guide.
- Ní / Nic: the traditional feminine forms (“daughter of”) — met in Irish-language records and revived usage.
- Fitz-: Norman “son of” (French fils) — FitzGerald, FitzPatrick.
- Anglicisation: the rendering of Irish names into English by sound or translation — the reason one family answers to three surnames; mechanisms and reversals here.
- Pet-name traps: Bridget→Bridie/Delia, Honora→Nora/Onny, Margaret→Peg/Madge, Mary→Molly/May — the same woman, four records.
- Naming pattern (traditional): first son after the father’s father, second after the mother’s father, first daughter after the mother’s mother — a custom, not a law, but a genuinely useful hypothesis-generator for missing grandparents’ names.
Terms You’ll Meet in Land and Legal Records
- Occupier / immediate lessor: Griffith’s pair — the householder, and whom they held from.
- In fee: outright ownership — rare and notable in Griffith’s.
- House, offices and land: “offices” are farm outbuildings, not workplaces.
- Memorial (Registry of Deeds): the registered summary of a deed — the searchable trace of leases and settlements from 1708.
- Calendar (probate): the annual index of wills and administrations — surviving from 1858 even where the wills burned.
Frequently Asked Questions
What is the single most misunderstood term in Irish research?
“Townland” — beginners hear “town” and search for streets. It is a rural land division, usually a scatter of farms; understanding that one word reorganises every record you read afterwards.
Do I need to learn Latin for Irish genealogy?
Only a postcard’s worth — the registers use perhaps thirty formulaic words, listed above. An evening with one parish’s pages and the formulas read themselves.
Why do the same places and people have multiple spellings?
Because everything was transliterated Irish written down by ear, in an era of fluid spelling and frequent illiteracy. Treat every name — person or place — as a sound with several costumes, and search accordingly.
Vocabulary Is Velocity
Every term above buys back hours of confusion somewhere in the records. Keep this page open beside the tracing method, and the documents start speaking plainly.
Want the shortcut? Grab the free Irish Genealogy Starter Checklist — the ten records to find first, and exactly which free database holds each one.
