kangaroo court

US /ˌkæŋ.ɡəˈruː ˌkɔːrt/
UK /ˌkæŋ.ɡəˈruː ˌkɔːrt/
"kangaroo court" picture
1.

an unofficial court held by a group of people, especially in a prison, in order to punish someone for breaking rules

:
The prisoners held a kangaroo court to decide the fate of the informant.
He was subjected to a kangaroo court where he had no chance to defend himself.
2.

a court that ignores due process and legal rights, often reaching a predetermined verdict

:
The defendant claimed the entire trial was a kangaroo court.
Justice cannot be served in a kangaroo court.