Millsap
A surname most likely from a place-name or a descriptive nickname built from the words for a mill and a low-lying wet area.
The #7,138 most common surname in the United States (2010 Census) — about 1 in every 65,901 Americans shares it.
Etymology
Millsap is probably English in form and likely began as a topographic surname. The first element is usually understood as Middle English mill, "mill," while the second may reflect a dialect word related to sap or sopp, meaning a boggy, wet, or low-lying place. In that sense, the name would originally have referred to someone who lived near a mill by marshy ground, or to a settlement so described. Because the surname is relatively uncommon, a precise single derivation is less certain than for many older English names.
History
The name is found chiefly in English-speaking countries, especially the United States, where it appears to have been carried by descendants of British settlers. As with many uncommon surnames, spelling has likely remained fairly stable in modern records, though earlier forms could have varied. Without an early documentary trail, it is hard to tie the name securely to one specific village or family line.
Origin
Regions
Variant spellings
Fun fact
Its shape makes it look almost like a phrase, which is one reason it is memorable even though the surname is relatively rare.