Etymology

Originally The Bailey, a street running outside the western wall of medieval London; from the word "bailey," a Middle English term for the outermost wall or court of a fortification. The courthouse built nearby in the 16th century, alongside old Newgate Prison, took its name from the street.

Proper noun

Old Bailey

1. a street in the City between Holborn circus and St Paul's Cathedral
2. the Central Criminal Court in this street