Main
Usually from the old personal name Main, but in some families it may also point to the French province of Maine.
The #2,824 most common surname in the United States (2010 Census) — about 1 in every 24,166 Americans shares it.
Etymology
One common origin is from an early Germanic personal name based on a word meaning "strength" or "power." In the Old Teutonic languages, this element appears in forms like Old English, Old Norse, and Old High German names. Another possible source is the French province of Maine, ultimately from the Latinized name of the region.
History
Medieval records show the surname very early in English use as a patronymic, such as "son of Main" forms in 12th-century Northumberland. Later writers also noted a separate French locational source from Maine, which would have entered England through Norman and Anglo-Norman connections. Because both forms existed, the surname can have more than one origin depending on the family line.
Origin
Regions
Variant spellings
Fun fact
Lower noted that the related surname Mainwaring had been spelled in an astonishing number of forms in old records, showing how fluid surname spelling could be.
From the historical record
“MAIN "1 (Teut.) Strength [M.E. mazH, O.E. MM^E]mcegen = O.Sax., O.N., O.H.Ger. megin, strength, power (a fairly common element in O.Teut. names] (Fr.-Celt.) One from the Duchy of Maine [Fr. Maine, the Lat.-Celt. Cenoma-”
— Surnames of the United Kingdom: a concise etymological dictionary (2 vols in 1)