Other forms: thoroughbreds
A thoroughbred is a horse of pure and recorded breeding. A thoroughbred colt, race thoroughbreds, a thoroughbred stud.
Every one alive descends from three stallions brought to England around 1700, which makes the whole breed a closed and narrow gene pool. The word is used loosely of any well-bred animal and precisely of racehorses. Thorough here means complete.
1nounthoroughbredA horse of pure and recorded breeding.
“The thoroughbred won the race by several lengths.”
thoroughbred is a horse.
Thorough plus bred, from thorough in the old sense of complete or through and through.
From thorough + bred.
Etymology from Wiktionary, CC BY-SA