1British a body established to settle certain types of dispute:an industrial tribunal ruled that he was unfairly dismissed
2a court of justice:an international war crimes tribunal
a seat or bench for a judge or judges.
late Middle English (denoting a seat for judges): from Old French, or from Latin tribunal 'raised platform provided for magistrate's seats', from tribunus(see tribune1). tribunal (sense 1) dates from the early 20th century
tribunal in other Oxford dictionaries
Definition of tribunal in the US English dictionary