late 14c., "of or pertaining to a judge; pertaining to the administration of justice," from Latin iudicalis "of or belonging to a court of justice," from iudicium "judgment, decision of a court of justice," also the court itself, from iudex "a judge," a compound of ius "right, law" (see just (adj.)) + root of dicere "to say" (from PIE root *deik- "to show," also "pronounce solemnly"). Related: Judicially.