1. a person who thinks they know everything; someone who always thinks they're right and annoys the shit out of everyone.
2. someone who exaggerates stories when telling them to someone else
1. - No, that's not how you do it. I've done this like a million times. You're doing it wrong.
- Quit being a mooney. Chill, son.
2. - ...And I was like, "whoa get off my girl," and he punched that other dude in the face.
-That never happened. You're a mooney. And a bitch.