It is the truth. (Can be posed as a question as well as a response.) A: "You really said that to him?" B: "No lie—you should have seen his face when I did!" A: "They said I'd be getting a 20% bonus this year!" B: "No lie? Wow, that's fantastic!"
exclam. Honest!; No kidding! I was there on time. No lie! Ask my sister.
See also: no