Best definition
what’s loose?
What’s up? What’s going on?Typically used as an actual question, rather than as a greeting (sup yo!)Depending on tone of

voice, may also be used in a state of anger, surprise or upset.

Frat 1: wohaa what’s loose?!

Frat 2: You’re mama’s what’s loose!

Frat 1: No I mean, what is going on here?!

Frat 2: Yeah, and I mean your mama’s what’s going on here!