WordWeb Online

1. One chap's arbitrary assertion
    
2. An authoritative declaration
   - pronouncement, dictum
    
3. The power or right to give orders or make decisions
   "he has the say-so to issue warrants";
   - authority, authorization, authorisation [Brit], potency, dominance

Derived forms: say-sos

Type of: affirmation, assertion, control, declaration, statement