Green’s Dictionary of Slang

whodunnit n.

[SE whodunnit, a murder mystery; the ‘murder victim’ is the prison cat]

(UK prison) meat pie.

1950
1950196019701980
1989
Show quotations
[UK]P. Tempest Lag’s Lex. 230: ‘who dunnit’ [...] A meat pie. ‘Who killed the prison cat?’.
[UK]J. Morton Lowspeak.