Define Being A Jack Meaning

Being Jack
When you are being jack you are dismissing someone by claiming you don't know them.

I'm being Jack with Chris by acting like I don't know him
By Maryjane
Being A Jack
This is when someone (usually named jack) is hiding their sexuality for example they are gay but will hide it and make fun of other heterosexual males calling them gay on the off chance he can convert one of them so therefore when he comes out the closet he isn't alone.

Hey you, why you being a Jack? No one likes a Jack.
By Caprice
Being A Jack
Being unbelievably stupid and saying dumb things

Person 1: Hes not ethiopian hes christian
Person 2: Stop being a jack
By Chelsey