"decree issued by a Russian emperor," 1729, from Russian ukaz "edict," back-formation from ukazat' "to show, decree, to order," from Old Church Slavonic ukazati, from u- "away," perhaps here an intensive prefix, from PIE *au- (2) "off, away" + kazati "to show, order," from Slavic *kaz- (related to the first element of Casimir), from PIE root *kwek- "to appear, show."