1. not in accordance with fact or reality; false
2. not faithful or loyal; disloyal
Usage: somewhat formal

Examples

• The witness gave untrue testimony during the trial.
• It would be untrue to say that all teenagers are irresponsible.
• The newspaper printed an untrue story about the mayor.
• She felt he had been untrue to their friendship.
• The rumor about the school closing was completely untrue.
• His untrue behavior damaged their relationship.
• The advertisement made several untrue claims about the product.