The deportees were returned to their home country due to illegal entry.

deportees 是由动词 deport（驱逐出境）加上后缀 -ee 构成的名词。后缀 -ee 通常表示"受动者"，即"被...的人"。因此 deportee 指"被驱逐出境的人"，复数形式是 deportees。