The term "jobby job" is a common one used among college students. It is used to refer to a job one hopes to have some day, after graduation.
This term is used for two reasons. First, a person might have a job, but not be satisfied. Saying that one looks forward to graduating and getting a job is not exactly accurate, as a mere job may be attained without a college degree. Thus, a 'jobby job' is a job one actually wishes to have.
Also, a college student may not know exactly what sort of job he or she wants after graduation. A degree in a particular field may qualify a graduate for any number of jobs. The term 'jobby job' serves the purpose of referring to this unknown future job in a general sense, while still distinguishing it from the multitude of other options.
Example: "Once I graduate and find a jobby job, I can afford to eat something other than ramen."