[Origin unknown.] The sweet-bread of a calf, sheep, etc.
1573. Art of Limming, 10 b. To take grease out of parchement or paper. Take sheeps burres & burne them to pouder, [etc.].
1730–6. Bailey, s.v., The Bur of a Beef, &c., the sweet bread.
1752. F. Coventry, Hist. Pompey the Litt., 125. Sitting down to a breast of veal … raving at the landlord, because the bur was gone.
1834. Esther Copley, Housekpr.’s Guide (1838), 124. A sweetbread (or burr) is sometimes boiled and served with parsley and butter.
