This term is used when you wish to call out your friends or foes on telling a lie. This word can be used interchangeable with the word "bullshit" and the phrase "you're lying."
Luke: "I really like the band 5 Seconds of Summer."
Becca and Ella: "Are you serious? They are the worst band ever!"
Luke: "Wait did I say 5 Second of Summer, I meant Doja Cat."
Becca and Ella: "Jeens"