MacNab is an anglicized Scottish Gaelic surname from Mac an Aba, literally son of the abbot. The name is particularly associated with Glen Dochart in Perthshire. That regional and clan association is historically meaningful, but the surname alone does not prove descent from a particular abbot, clan chief, or Glen Dochart family.
The Gaelic Construction
The name has three parts: Gaelic mac means son, an means of the, and aba is the form of the word for abbot used in the phrase. Modern surname dictionaries also print the source as Mac an Aba(dh), reflecting variant Gaelic spelling. The Scottish Gaelic dictionary Am Faclair Beag gives aba as “abbot,” while Scotland's People explains both the @@5@@ construction and MacNab's literal meaning.
This is a relationship name built from a title or status: it originally identified a son or descendant associated with an abbot. It does not mean that later MacNabs worked as abbots, nor should it be read as a modern occupational surname. Once inherited surnames became established, the literal relationship no longer had to describe each bearer.
What “Abbot” Meant in This Context
The apparently awkward idea of an abbot having descendants makes more sense in the setting of the medieval Gaelic church. George F. Black's The Surnames of Scotland interprets the early chiefs as probably connected with the lay abbacy of Glendochart and explains that some ecclesiastical offices and their lands passed within leading local families. The Dictionary of American Family Names likewise notes the role of hereditary lay abbots in Scotland.
That explanation is plausible historical context, not proof of one named founder. “Son of the abbot” may preserve real or asserted descent from an office-holder, but the surviving surname cannot by itself identify which abbot was meant. It is therefore safer to call MacNab a Gaelic relationship surname referring to an abbot than to describe every MacNab as the descendant of a monk.
Documented Medieval and Early-Modern Forms
Black cites two men recorded in 1376: Mathew M'Nab, a tenant in Brekauchbeg in the barony of Buittle, and Maurice M'Nab, a tenant in Glenwaldy in the barony of Preston. He also records Robert Gynnab, a Scottish prisoner released at Colchester in 1396; Patrick M'Gynnab of Bovain, whose death was recorded in 1488; and Finlai M'Genab de Bowayn, whose death was placed in 1525. These examples show both the age of the surname in written records and the wide variation clerks used for the same Gaelic name.
Those dated forms are evidence for people who bore the name; they are not a continuous pedigree and should not be turned into an “earliest ancestor” for modern families. In particular, medieval people styled “of Glendochart” are sometimes included in clan narratives, but a territorial designation is not automatically the surname MacNab.
Later forms collected by Black include Maknabe and M'Knabe in 1591, M'Knab in 1598, Milnab in 1643, Makinnab in 1647, and McNap in 1692. Their differences reflect recordkeeping and anglicization rather than a tidy sequence in which one official spelling replaced another.
Glen Dochart and Clan Tradition
Glen Dochart is not merely a modern clan attribution. Historic Environment Scotland describes Kinnell House at Killin as a former seat of the Macnab clan, with possible fabric from about 1580. Its record for the MacNab burial place on Innis Bhuidhe, an island in the River Dochart, says the present formal arrangement is largely late eighteenth-century while the site's burial use may be older. These physical sites support a substantial MacNab presence around Killin without proving the ancestry of every bearer.
Clan tradition goes further. One account makes the founder Abraruadh, a ninth-century abbot of Glen Dochart and supposed son of Kenneth MacAlpin; another places a founding lay abbot in the reign of David I (1124–1153). The Dictionary of American Family Names reports both as traditions, not as settled documentary conclusions. They should not be blended into a single biography or treated as a verified line back to the ninth century.
MacNab, McNab, and Other Spellings
MacNab and McNab are the principal modern forms. In Scottish records, Mc, Mac, and M' were alternative ways of representing the Gaelic prefix. Scotland's People warns that even the same person may be indexed under @@5@@ in one record and @@6@@ in another, so the choice between MacNab and McNab is not evidence of a different lineage.
Useful forms to recognize include:
MacNabandMcNabM'Nab,M'Knab, andM'KnabeMaknabeandMakinnabM'Gynnab,Gynnab, andM'GenabMcNabb, a doubled-bvariant recognized by a modern surname dictionary
Similar spelling still requires corroboration from place, date, relatives, and original records. McNabb is treated as a variant of McNab in the 2022 Dictionary of American Family Names, but that linguistic relationship does not make all families with the two spellings genealogically connected.
There is also a useful ambiguity with Abbot and Abbott. The Oxford Dictionary of Family Names in Britain and Ireland notes that Scottish Abbot can sometimes be an anglicization of Gaelic McNab. Most English Abbott families, however, have a separate surname history. A translated form is therefore a possibility to investigate in a particular record set, not a universal equivalence.
A Documented Canadian Episode
The surname's Canadian history has a particularly concrete Glen Dochart connection. According to the Dictionary of Canadian Biography, Archibald McNab, seventeenth chief, was born about 1781 at Bouvain in Glen Dochart. After inheriting a heavily mortgaged estate, he fled to Upper Canada and by February 1823 was petitioning for land on the Ottawa River. The first group of settlers in his controversial McNab Township scheme arrived from Scotland in 1825.
This episode documents movement of a specific MacNab clan figure and Scottish settlers to what is now Ontario; it should not be generalized into the migration story of every Canadian MacNab. Another well-documented bearer, Sir Allan Napier MacNab, was born in Upper Canada in 1798 and became a soldier, lawyer, businessman, and politician. Together the two biographies show that the name was established in Upper Canada by the early nineteenth century through more than one family setting.
Etymology Is Not Genealogy
The literal meaning supplies linguistic history, while Glen Dochart supplies important regional context. Neither supplies an individual family tree. A bearer may use MacNab, McNab, or a historical variant; may belong to a documented clan branch; may descend from Scottish migrants elsewhere; or may have a northern Irish family history, as modern surname dictionaries also record. Each conclusion needs evidence independent of the name's meaning.
References
- Black, George F. The Surnames of Scotland: Their Origin, Meaning, and History. New York Public Library, 1946. Open Library edition record.
- Hanks, Patrick, Simon Lenarčič, and Peter McClure, eds. Dictionary of American Family Names. 2nd ed. Oxford University Press, 2022. Ancestry: McNab entry and McNabb entry.
- Hanks, Patrick, Richard Coates, and Peter McClure, eds. The Oxford Dictionary of Family Names in Britain and Ireland. Oxford University Press, 2016. Publisher's preview.
- National Records of Scotland. “Surnames,” *Scotland's People*.
- Historic Environment Scotland. “Killin, Kinnell House including walled garden and ancillary buildings” (LB8283) and “Killin, Island of Inchbuie, Clan MacNab burial place” (LB8277).
- *Am Faclair Beag*: @@0@@, “abbot”.
- Cameron, Alan, and Julian Gwyn. “McNAB, Archibald, 17th Chief of Clan MacNAB,” Dictionary of Canadian Biography, vol. 8, University of Toronto/Université Laval, 1985.
- Baskerville, Peter. “MacNAB, Sir Allan Napier,” Dictionary of Canadian Biography, vol. 9, University of Toronto/Université Laval, 1976.