ukase
An authoritative proclamation; an edict, especially decreed by a Russian czar or later ruler.
Many estates peopled with crown peasants have been, according to an ukase of Peter the Great, ceded to particular individuals on condition of establishing manufactories […]
Any absolutist order or arrogant proclamation
figuratively
I knew a stunned plunge of disappointment and a bitter anger. What right had he to issue such an arbitrary ukase?
Where it comes from
Borrowed from Russian ука́з (ukáz, “edict, decree”).
Adapted from the Wiktionary entry ukase (CC BY-SA 4.0).