1 definition by Hdbakdbejfbd
A suburb just outside of Philadelphia known for its reputation of preppy schools, moms, kids, and pretty much everything else. All of the private schools including The Haverford School, The Baldwin School, The Agnes Irwin School, and The Episcopal Academy, are known for their great education and scandalous secrets. To sum it all up the mainline is like the 90210 with rich preppy families who send their children to private schools just to show off how much money they have. The mainline is a community of dirty, rich, and prestigious people who will do anything to one up anyone else.
Don't trust the people on the main line
by Hdbakdbejfbd July 2, 2014