An unofficial court or a court that disregards current laws and conducts unfair trials. People who live under oppressive regimes are often treated harshly by corrupt kangaroo courts that don't abide by the law.
A self-appointed tribunal that violates established legal procedure; also, a dishonest or incompetent court of law. For example, The rebels set up a kangaroo court and condemned the prisoners to summary execution, or That judge runs a kangaroo court-he tells rape victims they should have been more careful . This expression is thought to liken the jumping ability of kangaroos to a court that jumps to conclusions on an invalid basis. [Mid-1800s]