Jacker is a highly offensive and dangerous slang in the world of rap, so you better be warned when you use it.
In the dangerous urban streets, jackers make a living out of robbing others. This relates to how it is used in a rapping context.
Jackers are other rappers with no originality and primarily steal other artists’ verses, style, lyrics, and beat. Jackers are rotten eggs that should not be emulated. Here are some examples of its usage.
“Bruno Mars has been called a Jacker and got sued.”
“Katy Perry was thought to be Jacker because her song “Dark Horse” had some issues.”