Underhill
A topographic surname for someone who lived beneath or at the foot of a hill.
The #5,119 most common surname in the United States (2010 Census) — about 1 in every 45,145 Americans shares it.
Etymology
Underhill comes from Old English under, meaning "under" or "below," plus hyll, meaning "hill." The name was originally descriptive of where a person lived: literally, "the one dwelling under the hill." The same idea appears in medieval records as forms like Underwode and Undrell, showing a stable place-based naming pattern.
History
Medieval English records show the surname in use by the 13th and 14th centuries, and the spelling has varied over time. It is a straightforward English topographic name rather than a clan or occupation name. Later bearers spread through England and, eventually, to North America and other English-speaking regions.
Origin
Regions
Variant spellings
Fun fact
19th-century surname writers also note Underdown and Underwood as closely related topographic surnames built on the same simple "under + landscape feature" pattern.
From the historical record
“under ; and v. Hay] UNDERHILL (Eng.) Dweller Under the Hill [O.E. under; hyll] William Underhiil.— ffM«d. Rolls. UNDERWOOD (Eng.) Dweller Under the Wood [O.E. under ; wudu, dat. wuda] John Underwode. — Hund. Rolls, A.D. 1274. Adam Undirwode. —”
— Surnames of the United Kingdom: a concise etymological dictionary (2 vols in 1)