Definition of "untrue"

"I know it is true, for an untrue word never passed her lips."

1886, Peter Christen Asbjørnsen, translated by H.L. Brækstad, Folk and Fairy Tales, page 11

This statement is untrue.

2004, George Carlin, When Will Jesus Bring the Pork Chops?‎, New York: Hyperion Books, page 264

Now you say you're sorry / For being so untrue / Well, you can cry me a river, cry me a river

1953, Arthur Hamilton (lyrics and music), “Cry Me a River”

Let me be the one you come running to / I'll never be untrue

1971, “Let's Stay Together”, performed by Al Green

Tonight you didn't come / And my senses all were reeling / I had a certain scary feeling you'd been untrue

2019, “The Night You Didn't Come”, in Becoming Peter Ivers, performed by Peter Ivers