The definition of lying is not telling the truth.
An example of someone who is lying is someone who is dishonest about where he was and what he did.
Present participle of lie1
- She couldn't help feeling disappointed; space looked no different than it had when she was lying on the roof of Evelyn's house.
- They're lying on your bed.
- "No, Lacy—" "You've been lying to Jake, too.
- I wasn't lying, I just wasn't telling everything.
- He was lying, sure enough.