certify (v.)

• accept
• accredit
• acknowledge
• affirm
• allege
• approve
• ascertain
• assert
• asseverate
• assure
• attest
• authenticate
• authorize
• autograph
• aver
• avouch
• avow
• back
• bolster
• bond
• book
• buttress
• certificate
• charter
• cinch
• circumstantiate
• classify
• clinch
• commission
• confirm
• corroborate
• cosign
• countersign
• decide
• declare
• depone
• depose
• determine
• disclose
• document
• empower
• enable
• endorse
• enfranchise
• ensure
• entitle
• establish
• fix
• fortify
• franchise
• guarantee
• initial
• insure
• legalize
• legitimize
• license
• notarize
• pass
• patent
• permit
• privilege
• probate
• profess
• prove
• ratify
• reassure
• reinforce
• sanction
• seal
• second
• secure
• settle
• sign
• sponsor
• strengthen
• substantiate
• support
• sustain
• swear
• testify
• undergird
• undersign
• underwrite
• uphold
• validate
• verify
• visa
• vise
• vouch
• vouchsafe
• vow
• warrant
• witness