Mai
A surname with multiple possible origins, including Irish Gaelic patronymic roots and, in some cases, a form related to May or a byname.
The #2,075 most common surname in the United States (2010 Census) — about 1 in every 17,698 Americans shares it.
Etymology
The surname Mai is ambiguous in the historical dictionaries. Lower treats it as an Irish form, describing it as the genitive of a Gaelic patronymic name, while his related note on May says that written records often show forms like "le Mai" rather than any connection with the month of May. Harrison also points to possible links with forms of Mayer/Mayor and with Anglo-French Mair(e), meaning mayor. In short, Mai may represent different surnames in different families, rather than one single origin.
History
In English and Irish records the spelling can be very short and unstable, which makes this surname hard to pin down. Some bearers may descend from Gaelic family names that were shortened or anglicized, while others may reflect French or occupational forms connected with a mayor. Because of that, the same spelling has likely been applied to more than one unrelated family line.
Origin
Regions
Variant spellings
Fun fact
Lower explicitly warned that the surname May in records was not necessarily connected with the month of May, which shows how misleading a simple modern spelling can be.
From the historical record
“MAIR "I I Scot, forms of Mayer or Mayor, MAI RE/ , q.v. [Gael, waor, an officer] 2 the A.-French Mair(e = Mayor, q.v. Ne to be mair above men Ne mynystre under kynges. — Piers Plowman, 9486-7. MAISEY "1 (Celt.) .Fair, Handsome [Gael. MAIZEYJ maiseacK]”
— Surnames of the United Kingdom: a concise etymological dictionary (2 vols in 1)