Italian slang used in the show "It's Always Sunny in Philadelphia". Possibly used to insult a person for various reasons.
1. Charlie: "Just glide one puck just to get the hang of it."
Mac: "Gliding like a jabroni is what I'm gonna be doing."
2. Charlie: "You keep using this word 'jabroni'...and it's awesome!"
Mac: "Yeah I think it's some daigo word or something"
A Jabroni is someone who sucks. Jabroni's are often inferior in skills such as light-sabering, dancing, or playing video games. Jabroni's can not make decent cocktails.