Hair
Usually an English nickname surname for someone with notable hair—or, in Irish usage, a form linked to O'Hehir.
The #4,539 most common surname in the United States (2010 Census) — about 1 in every 39,512 Americans shares it.
Etymology
The surname Hair has more than one possible origin. In English, it is naturally read as a nickname from the word hair, probably first used for someone with a distinctive head of hair or hair color. Some older writers also treated it as a corruption of heir, but that explanation is less secure and may apply to only some families. In Ireland, Hair is also found as an anglicized form of older Gaelic surnames such as O'Hehir (earlier spellings like O'Tehir / O'Hehir appear in historical records).
History
English Hair is the kind of short nickname surname that often arose in the Middle Ages and then became hereditary. The Irish family line cited by Lower was associated with chiefs in west-central Ireland and is historically documented by the 14th century, though later traditions pushed the family much farther back. Because the spelling is short and very plain, the same form may represent unrelated English and Irish origins in different families.
Origin
Regions
Variant spellings
Fun fact
A 19th-century surname dictionary explicitly noted Hair as an Irish surname written O'Tehir before about 1770.
From the historical record
“Ainulph. HAIR. A coiTuption of heir, the eldest son. HAIRE. This Irish surname, previously to the year 1770, was written OTIehir. The traditions of the family deduce them from the race of Fingal in the third cent., but historical evidence carries them back no further than the reign of Edw. III., 1365, when the…”
— Patronymica Britannica: a dictionary of the family names of the United Kingdom