Noun
truth [pl. truths]
honesty [pl. honesties]
sincerity [pl. sincerities]
truthfulness {feelings & emotions}
veracity [pl. veracities] , {feelings & emotions}
verity [pl. verities]
Verb
to believe [ believed ; believed ]
to say the truth {tell, speak}
to validate [ validated ; validated ]
to ratify [ ratified ; ratified ]
to notarize [ notarized ; notarized ]
to indorse [ indorsed ; indorsed ]
to endorse [ endorsed ; endorsed ]