A judicial proceeding or trial which has a predetermined outcome or where the basic legal rights of a party are jumped over.
In Nebraska State Bar Association v Rhodes 177 Neb 650 (1964), the Supreme Court of Nebraska used these words in regards to kangaroo court:
"An irresponsible, unauthorized, or irregular tribunal, or one in which, although conducted under some authorization, the principles of law and justice are disregarded or perverted."
In that case, the description of a judicial body as a kangaroo court was held to constitute contempt of court.
In Lamb v Clark 282 Ky 167 (1940), the Court of Appeals of Kentucky had occasion to describe an ad hoc trial of new prisoners to jails in Graves County as kangaroo court; with the pre-determined and inevitably result of the whiping and beating of new prisoners as a form of prison initiation.
In Clark v Chief Constable of Essex Police 2006 EWHC 2290 (QB), published at bailii.org/ew/cases/EWHC/QB/2006/2290.html, the British High Court of Justice appeared to accept the description of kangaroo court in the context of a disciplinary proceeding "because those attending jumped from the accusation to the condemnation without pausing to find out what the accused person had to say about it."