The adverb: doing something in a way that is not true — saying something while knowing it is false. It attaches to verbs of speaking and reporting: answer untruthfully, claim untruthfully, state untruthfully, testify untruthfully. Its natural home is formal and legal writing, where the exact wording matters: 'He untruthfully claimed to have a medical degree.' Notice where it likes to sit — most often right before the verb, or just after it ('he untruthfully stated' / 'he stated untruthfully'), rather than at the end of the sentence. It is quite a heavy, bookish word, and in ordinary conversation almost nobody uses it; people say 'he lied about it' instead. The key idea it carries is deliberateness. Saying someone answered untruthfully is saying they chose to give a false answer, not that they made a mistake — which is exactly why courts and official reports prefer it.

不實地、說謊地（多用於正式或法律語境，如「不實陳述」）