Synonyms for Authority (same or very similar meaning)
WordNet sense 1 (an administrative unit of government):
agency, bureau, office, federal agency, government agency
WordNet sense 2 (freedom from doubt; belief in yourself and your abilities):
assurance, confidence, self-assurance, self-confidence, sureness
WordNet sense 3 (the power or right to give orders or make decisions):
authorization, dominance, potency, say-so, authorisation
WordNet sense 4 (official permission or approval):
sanction
From the ODE community, based on WordNet
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