Definition from Wiktionary, the free dictionary
- Any mass educational system of improving or providing conditions to increase the intellectual quality and yield of a population of (human) brains, e.g. a university or school.
- [a. 1928] 1960, “Brains,” in Life and Works of Woodbridge N. Ferris, Roy Newton ed. 
- Confidentially, most people have brains, but they are not using them. They have left their own brain farms and gone out into the highways and byways, slaves to the intelligence of those who they call bosses, the few owners of the earth.
- 1995, Sailor Moon, Episode 5, “Computer School Blues” 
- — I heard some new girl has transferred here, and she's a total brainiac.
- — Yeah, she's from Brighton Academy.
- — The brain farm?
1998, Jay Mathews, Class Struggle:
- To the parents and the students involved, the schools have one function. They are brain farms. The parents plant their children in the school because it has a reputation for turning out well-regarded college applicants.
- [a. 1928] 1960, “Brains,” in Life and Works of Woodbridge N. Ferris, Roy Newton ed.