Despite having a master's degree, he is underemployed and can only find part-time jobs due to the economic downturn.

underemployed 是由前缀 under-（表示"不足、低于"）和 employed（被雇佣的）组成的形容词。under- 表示程度不足，employed 来自动词 employ（雇佣）。合起来指"就业不足的"，即虽然有工作但工作时间和收入低于预期或能力水平的状态，常译为"半失业"或"就业不足"。