tenderloin

noun

1. (in beef or pork) the tender meat of the muscle running through the sirloin and terminating before the ribs.
2. a cut of beef lying between the sirloin and ribs.
3. (initial capital letter)
   1. (formerly) a district in New York City noted for corruption and vice: so called because police there could eat well from their bribes.
   2. a similar district in any U.S. city.

noun

1. a tender cut of pork or other meat from between the sirloin and ribs
2. US a district of a city that is particularly noted for vice and corruption

n.1828, “tender part of a loin of pork or beef,” from tender (adj.) + loin. The slang meaning “police district noted for vice” appeared first 1887 in New York, on the notion of the neighborhood of the chief theaters, restaurants, etc., being the “juciest cut” for graft and blackmail.