Truthfulness is the habit of saying what is so. Doubt his truthfulness, the truthfulness of the account, judge for truthfulness.
It is about the speaker rather than the statement, since somebody truthful can be honestly wrong. That distinction is why courts assess a witness for truthfulness and reliability as two separate things.
1nountruthfulnessThe habit of saying what is so.
“Parents value truthfulness in their children above almost anything else.”
truthfulness is a quality.
From truthful + -ness.
Etymology from Wiktionary, CC BY-SA