floater
noun [ C ] uk/ˈfləʊ.tər/ us/ˈfloʊ.t̬ɚ/
(SPOT IN EYE)
（因为飞蚊症）眼睛看到的（不存在的）浮游物
a small spot inside a person's eye that they see moving up and down or from side to side
(PERSON)
mainly US临时工，无固定工作的人;在同一个组织里做很多不同工作的人
someone who does a lot of different jobs in an organization
He had worked as a floater, assigned to any of the fire stations across the county as the need arose. 他曾做过流动工人，需要时被分配到全国各地的消防站工作。