Truthful rhymes with:
untruthful, untruthful, untruthful, youthful, faithful, healthful, unfaithful, unhealthful, untruthful, youthful
Truthful sounds like:
tradable, tradeable, treatable, truthfully
untruthful, untruthful, untruthful, youthful, faithful, healthful, unfaithful, unhealthful, untruthful, youthful
tradable, tradeable, treatable, truthfully