Green’s Dictionary of Slang

dish n.2

[dish v. (1)/dish v. (3)]

1. the act of abusing, cheating.

[UK]Partridge DSUE (8th edn) 314/1: 1891.

2. an embarrassing story about a subject’s life.

[US]Russo ‘Camp’ in Levine Gay Men (1979) 209: Calculated camp, packaged so that people will think she’s bringing them the real ‘dish’ from the inside.
[US]A. Maupin More Tales of the City (1984) 36: Charles Hillary Lord needed more dish [...] ‘DeDe’s been doing it with an Ornamental?’.
[US]Hope College ‘Dict. of New Terms’ 🌐 dish n. A slang term for information or gossip, commonly used by teenagers.
[US]E. Weiner Big Boat to Bye-Bye 22: Ellen [...] threw I’ve-got-dish eyes at Stephanie, and dragged her off to the side.
[US]J. Ellroy Widespread Panic 4: It’s the lexicon of the lowdown. It’s the dialogue of the dish.

In phrases

know the dish (v.)

(US black) to be aware of the, usu. embarrassing, truth.

Phoebe Phoebe’s Web Page Stanford University 🌐 Tony’s a great drinking mate. Whenever I need to know the dish on a good bar or fun places in general, Tony’s the man.
dump the dish (on) (v.)

to reveal (embarassing) secrets (about).

[US]J. Ellroy Widespread Panic 4: I dumped the dish on his dope habit and call-girl cavalcade .