WordWeb Online

1. Declare or make legally valid
   - formalize, formalise [Brit]
    
2. Prove valid; show or confirm the validity of something
    
3. Give evidence for
   - corroborate
    
4. Make valid or confirm the validity of
   "validate a ticket"

Derived forms: validates, validated, validating

Type of: affirm, alter, authorise [Brit], authorize, change, clear, confirm, corroborate, modify, pass, reassert, substantiate, support, sustain

Antonym: annul, invalidate, nullify

Encyclopedia: Validate