1. Tested and proved useful or correct
   - tested, tried

See also: proved, proven

• secpar
• secrecy
• secret
• secret agent
• secret approval
• secret ballot
• secret code
• Secret Intelligence Service
• secret plan
• secret police
• Secret Service
• secret society
• secret writing
• secretaire
• secretarial
• secretarial assistant
• secretarial school
• secretariat
• secretariate
• secretary
• secretary bird
• Secretary General
• Secretary of Agriculture
• Secretary of Commerce
• Secretary of Commerce and Labor