Webster's Revised Unabridged Dictionary · 1913

Untruth

Untruth , noun

1.
The quality of being untrue; contrariety to truth; want of veracity; also, treachery; faithlessness; disloyalty. — Chaucer
2.
That which is untrue; a false assertion; a falsehood; a lie; also, an act of treachery or disloyalty. — Shakespeare