https://blog.dol.gov/2016/09/06/what-is-the-real-unemployment-rate/

In BLS publications, the official unemployment rate is referred to as

the U-3. Though the U-3 gets the most attention, BLS also publishes

five other measures

of labor underutilization (U-1, U-2, U-4, U-5, and U-6), each of which

measure labor underutilization in a different way. The broadest measure –

the U-6 (sometimes referred to in the press as the “underemployment

rate”) – includes not just the officially unemployed, but also the

“marginally attached” (those who are neither working nor looking for

work but who want and are available to work and have looked for work in

the past year), and people who are working part-time but want a

full-time job. At its peak in the aftermath of the Great Recession, the

U-6 was 17.1 percent; it is now down to 9.7 percent.