pieces of broken wood and other waste materials found on the beach or floating on the sea

We wandered along the shore, stepping over the flotsam that had washed up in the night. 我们沿着海岸漫步，跨过夜晚冲上岸边的零碎杂物。

anything or anyone that is not wanted or not considered to be important or useful

The homeless sleep in doorways and stations - we step over their bodies like so much human flotsam. 无家可归的人睡在门口和车站——我们跨过他们的身体时就好像他们的存在毫无意义。