1) Affirm 2) Attest 3) Bear out 4) Circumstantiate 5) Confirm 6) Corroborate 7) Cosign 8) Okay 9) Prove 10) Ratify 11) Vet 1) Authenticate 2) Authorise 3) Authorize 4) Bear out 5) Clear 6) Confirm 7) Corroborate 8) Declare or make legally valid 9) Demonstrate 10) Endorse 11) Formalise 12) Formalize 13) Give credence 14) Give evidence for 15) Give legal force to 16) Legitimize 17) Pass 18) Prove 19) Prove valid 20) Ratify 
[McAfee] The Validate program by McAfee Associates is used to provide checksum data for computer programs and data files. It is commonly used to verify that shareware applications written for MS-DOS and Microsoft Windows based platforms have not been altered during distribution, (as would be the case if somehow the files had become infected...
• (v. t.) To confirm; to render valid; to give legal force to.
Val'i·date transitive verb [ See Valid .] To confirm; to render valid; to give legal force to. « The chamber of deputies . . . refusing to validate at once the election of an official candidate.» London Spectator. 
The process of checking submitted documents to ensure that they adhere to required formats.
[v] - declare or make legally valid 2. [v] - give evidence for 3. [v] - prove valid 4. [v] - make valid or confirm the validity of, as of a document
validate 1. To declare or make legally valid. 2. To mark with an indication of official sanction.
To establish or verify accuracy. For example, using measurements of temperature or precipitation to determine the accuracy of climate model results.
[SAT terms] show or confirm the effectiveness of something