kangaroo court

WordReference Random House Learner's Dictionary of American English © 2025

ˈkan•ga•roo ˈcourt, n. [countable]

1. a self-appointed or otherwise irregularly operated court or trial that disregards existing principles of law or human rights and thus makes a fair trial impossible.

WordReference Random House Unabridged Dictionary of American English © 2025

kan′garoo court′, 

1. a self-appointed or mob-operated tribunal that disregards or parodies existing principles of law or human rights, esp. one in a frontier area or among criminals in prison.
2. any crudely or irregularly operated court, esp. one so controlled as to render a fair trial impossible.
• 1850–55, American.

Collins Concise English Dictionary © HarperCollins Publishers::

kangaroo court noun

1. an irregular court, esp one set up by prisoners in a jail or by strikers to judge strikebreakers