Monahan
An Irish surname meaning “little monk,” from Gaelic words for “monk” plus a diminutive ending.
The #2,347 most common surname in the United States (2010 Census) — about 1 in every 19,877 Americans shares it.
Etymology
Monahan is generally explained as coming from Irish Gaelic manach, meaning “monk,” with a diminutive ending that gives the sense of “little monk” or “monkish one.” Historical spellings in old Irish surname studies include forms like Monaghan, Monachan, and related variants. The name is often treated as an Anglicized form of an older Gaelic family name built on this monk root.
History
The name appears in Irish genealogical and surname references chiefly as an anglicized Irish surname, with strong associations to counties such as Limerick, Clare, Tipperary, and Waterford in older surveys. 19th- and early-20th-century writers often grouped Monahan with Monaghan and similar forms because of their shared Gaelic root and overlapping spellings. In modern use it is established in Ireland and the Irish diaspora, including the United States.
Origin
Regions
Variant spellings
Fun fact
Older surname books sometimes linked Monahan and Monaghan to the same “monk” root, which is why the two names can appear side by side in historical indexes.
From the historical record
“MONACHAN ] (Celt.) Monk [Ir. and Gael, MONAGHAN \manach, a monk + the dim. MONAHAN J suff. -dn\ MONCKTON (Eng.) Bel. to Monckton, Monk- ton = the Monk's or Monks' Farm or Estate [O.E. munuc, a monk ; tiin, farm, &c.] Monkton, Kent occurs as Munccetun in a Latin charter of A.D. 961. Monkton, Durham, belonged to the…”
— Surnames of the United Kingdom: a concise etymological dictionary (2 vols in 1)