split decision noun2 •A decision that is not unanimous made by a panel of decision-makers, such as an appellate court.In a four-to-four split decision, with one concurring and four dissenting written opinions, the Second Circuit denied rehearing en banc. — 2017 •an outcome in several full-contact combat sports where two of the three judges score for the same fighter as the winner, while the third judge scores for the other fighter. formssplit decisions