Definition of "thoroughbreed"

thoroughbreed

noun
plural thoroughbreeds
1. A breed of unadulterated or pure lineage.
  Quotations
  No particular breed of cattle can be said to exist in this district: milk being the main object of the farmer, he does not consider any thoroughbreed particularly advantageous for that purpose; […]
  1844, The Farmer's Magazine, page 321
  SIR:—I have, at this moment, received from Dr. Eben Wight, the account of the stock of cattle known, in this vicinity, as the Jamestown. It is a cross between two thoroughbreeds — the Suffolk (no horned) on the part of the female, and the Jersey on the part of the male.
  1868, Annual Report of the Secretary - Volume 15, Part 1867, page 159
  It is only through the practice of the principles of evolution that a thorough-breed can be obtained. Every species is one of nature's thorough-breeds.
  1886, American Pomological Society, Proceedings, volume 20, page 96
  […] that all the progeny would have large berries and large clusters, and thus far [form?] a purebreed or thoroughbreed, of the “in and in bred” type would be secured.
  1899, Bulletin - Texas Agricultural Experiment Station
  Ellerslie is the most noted of modern Virginia thoroughbreed breeding establishments, and Eon, who was bred there, is one of the grandest looking thoroughbred stallions ever stripped.
  1903, The Southern Planter, volume 64, page 457
2. Alternative form of thoroughbred
  Quotations
  He also entered his own horses for the Lahore meetings, although the thoroughbreeds were sold off to trainers who competed in the more prestigious Bombay and Calcutta races.
  2013, Ian Talbot, Khizr Tiwana, the Punjab Unionist Party and the Partition of India