The phrase 'On Job' otherwise known as 'OJ' is typically given to a female who is renowned for giving multiple men uck and or performing sexual acts on them. A girl is given the title 'On Job' when she has successfully sucked at least 7 big ones.
Employees who just manage to show up, do the bare minimum, take long lunch breaks, disappear for hours, offer little or no ideas and are the first ones out the door.