A judicial or quasi-judicial proceeding, or a group which conducts such proceedings, which is without proper authority, abusive, or otherwise unjust
A military commission trial falling short of the full UCMJ standard is all but certain to be pejoratively judged as a kangaroo court in the court of public opinion.
disapproval If you refer to a court or a meeting as a kangaroo court, you disapprove of it because it is unofficial or unfair, and is intended to find someone guilty. an unofficial court that punishes people unfairly