Deitz
A German surname likely from a short form of names built on an old word for “people” or a related nickname form.
The #8,681 most common surname in the United States (2010 Census) — about 1 in every 81,592 Americans shares it.
Etymology
This surname is usually explained as a shortened form of a German personal name rather than a direct word meaning. The older scholarship in your excerpts points to forms built on the old Germanic element meaning “people, nation” (seen in names like Diet- and Theis-), though the exact path can vary by region and spelling. In some cases it may be related to diminutive or pet forms from the same name stock, which helps explain spellings such as Deitz, Deiss, and Theis.
History
The name fits a broader German pattern in which medieval given names were shortened and then inherited as surnames. Spellings varied widely in German-speaking areas, especially before standard spelling, so Deitz can appear alongside close forms like Deiss and Theis. In the United States it is a relatively uncommon surname, likely carried by immigrants from German-speaking Europe.
Origin
Regions
Variant spellings
Fun fact
The old Germanic name element behind this surname is the same broad root family that appears in many traditional names beginning with Diet- or Theis-.
From the historical record
“Deit- s. Thiud (V., einst E.j. Deitz s. 1) Dag (einst E.) 2) Thiud (einst. E.). Delir, Deilli s. Thiud (Y.).”
— Die deutschen Familiennamen