used to tell somebody the true facts about a situation, especially when these are not known by other people: None of the students really liked the new teacher. In fact, if the truth be told, everyone was rather afraid of him. To be perfectly honest, to present all the facts of a case.

Ellipsis of if the truth should be told. (idiomatic) Used when admitting something one might otherwise lie about, e.g. to keep up appearances or be polite. I'm not sure if I can do this, truth be told. Actually, truth be told, I just don't like you.