Someone with a lack of a work ethic. Someone who refuses to change their habits unless they are forced to do so.
"Kevin, get back to work you Jobber." - Alec "The Protector" Namdar
"Antonio Brown left his Jersey on the sideline, you know why? Because he is a fucking jobber, just like you. Be like Brady"
Someone without a job or someone who overworks their job. Could be used in the context of someone who needs to get a life.
He is a jobber, look at him jobberring around.
Someone who exists to lose spectacularly, to make something look more difficult than it is. This is so when someone doesn't fail they look better.
That character is only here to be a jobber and show how strong the other guy is.
Someone who treats their hobby as it were a career. Often these people proclaim how awesome they and their hobby/job are, but they can't pay the bills under that way of life. Hobby jobbers frequently are people like volunteer firefighters, volunteer emt, musicians, artists that take every opportunity to pat themselves on the back for their hobbies. They often are on food stamps, welfare and income tax ballers.
Did you see that facebook post from that hobby jobber at the fire department? She pretends like she does all this amazing stuff, but she can't even take care of herself and her 3 kids. Free school lunch, free health care, food stamps. She should probably worry about getting off probation and getting a real job,.
A burn-jobber is someone who is especially good at burning or roasting someone.
Some examples and places where this can be properly used as follows "I don't want to do the dishes" followed by "YOU ARE DISHES". The person that got burned is the Burnee and the person that said "You are dishes" is the burn-jobber.