confirms

affirm approve back certify corroborate endorse establish explain sign substantiate support uphold verify

attest authenticate bless buy check circumstantiate debunk double-check justify okay sanction settle subscribe underpin vouch warrant witness

bear out check out give green light give high sign give stamp of approval give the go-ahead give the nod lap up make good make sure rubber-stamp sign off on size up thumbs up

confuse contradict deny disallow disapprove discredit disprove invalidate oppose refuse reject

disagree refute veto

annul cancel destroy repudiate void

assure establish

buttress clinch fix fortify invigorate settle strengthen

make firm

discourage dishearten dissuade hurt unsettle weaken

annul cancel contradict deny destroy disprove invalidate oppose repudiate veto void