If a person or their comments are truthful, they are honest and do not tell any lies. We've all learnt to be fairly truthful about our personal lives She could not give him a truthful answer. + truthfully truth·ful·ly I answered all their questions truthfully. + truthfulness truth·ful·ness I can say, with absolute truthfulness, that I did not injure her
conforming to truth; "I wouldn't have told you this if it weren't so"; "a truthful statement"
expressing or given to expressing the truth; "a true statement"; "gave truthful testimony"; "a truthful person