Derr
Usually an Anglicized spelling of the German surname Doerr/ Dör, linked to the idea of a thorn or, in some cases, a personal nickname.
The #4,749 most common surname in the United States (2010 Census) — about 1 in every 41,409 Americans shares it.
Etymology
The cited source treats Derr as a simplified spelling of German Doerr (or Dör), where the German vowel sound was rendered in English spelling. In surname studies, this name is commonly connected with German words meaning "thorn" or with nicknames formed from a similar short root. Because the excerpt is incidental rather than a full dictionary entry, the exact derivation for every family line cannot be pinned down with certainty.
History
Derr is best understood as a German-American surname that became fixed in English spelling after immigration and naturalization. In many cases it reflects an earlier form such as Doerr, Dorr, or Dör, which were then simplified for English usage. The surname is relatively uncommon in the United States today, but it fits a broader pattern of German names losing umlauts and extra vowels in American records.
Origin
Regions
Variant spellings
Fun fact
German surnames with umlauts often shed them in America, so one family line might appear in records as Doerr, Dorr, or Derr.
From the historical record
“Hailman (Heilman), Espenshade (Espenscheid). The mixed vowels were simplified, b becoming e in Derr (Doerr), Kelker (Koellicker), ea in Early (Oehrle), Beam (Boehm), and a in Hake (Hoeck). Ue is long and short in German. The former gives ee, as in Keeney (Kuehne), Keeley (Kuehle) ; the latter usually gives z, as in…”
— Studies in Pennsylvania German Family Names