attest (v.)

• acknowledge
• affirm
• allege
• announce
• approve
• argue
• assert
• asseverate
• assure
• authenticate
• aver
• avouch
• avow
• back
• bespeak
• betoken
• bolster
• bond
• book
• breathe
• buttress
• certify
• circumstantiate
• confirm
• connote
• corroborate
• declare
• demonstrate
• denote
• depone
• depose
• disclose
• display
• document
• endorse
• ensure
• evidence
• evince
• exhibit
• express
• fortify
• guarantee
• illustrate
• imply
• indicate
• insure
• involve
• manifest
• mark
• probate
• prove
• ratify
• reinforce
• secure
• show
• sign
• signalize
• signify
• sponsor
• strengthen
• substantiate
• suggest
• support
• sustain
• swear
• tell
• testify
• undergird
• undersign
• underwrite
• uphold
• validate
• verify
• vouch
• vouchsafe
• vow
• warrant
• witness