Not working full time is the underemployed stat. I am very sure about these issues with BLS stats. My research professor for my grad degree did work in econometrics and always commented that the BLS unemployment series was manipulated to hell and back.
But what the hell do I know, not like the labor force participation rate is at historic lows... wait a minute, they are. At least, we aren't seeing a downward sloping Labor force participation rate that walks in step with a downward U3 and U6, indicating discouraged unemployment over 12 months. Oh wait... we are. Not like we are seeing increases in food stamp and public housing... oh we are.