fiat noun Stress: first syllable 🤍 Save Syllables: fi-at (2) English Definition A formal authorization or proposition; an arbitrary order. Example Sentence The new law was passed by royal fiat. US IPA /ˈfiːɑːt/ 🔊 Listen US UK IPA /ˈfiːæt/ 🔊 Listen UK Synonyms decree edict command order mandate Antonyms veto prohibition Share this Word Facebook WhatsApp X Telegram Copy Link