En banc

In law, an en banc session is one in which all the judges of a court sit to hear a case, not just one judge or a smaller panel of judges.
For courts like the United States Courts of Appeals, in which each case is normally heard by a three-judge panel instead of the entire court, an en banc review is usually used for only very complex or important cases or when the court believes there is an especially significant issue at stake. En banc is a French phrase meaning “in bench.” Convening an en banc court may enhance a court’s legitimacy by ensuring the quality and consistency of its case law and by signalling broad collective ownership of outcomes by all the court’s judges.