thoroughbred

thorough +‎ bred

thoroughbred (comparative more thoroughbred, superlative most thoroughbred)

1. Bred from pure stock.
2. Well-bred and properly educated.

• thoroughbreed

thoroughbred (plural thoroughbreds)

1. A horse of a breed derived from crosses between Arabian stallions and English mares, bred for racing. (usually capitalized: Thoroughbred.)
2. (nonstandard, loosely) Any purebred horse.
3. A person of uncommon strength or endurance (like that of a thoroughbred horse).

   That athlete is a real thoroughbred.

4. A well-bred person.

• thoroughbred on Wikipedia.Wikipedia
• thoroughbred at OneLook Dictionary Search
• thoroughbred in The Century Dictionary, The Century Co., New York, 1911