If someone is untruthful or if they say untruthful things, they are dishonest and say things that they know are not true. He must not be untruthful, or a coward Some people may be tempted to give untruthful answers. truthful. dishonest or not true
not expressing or given to expressing the truth; "the statement given under oath was untruthful"; "an untruthful person
not expressing or given to expressing the truth; "the statement given under oath was untruthful"; "an untruthful person"