nonentity|nonentities

在公司里，他只是个无足轻重的小人物，没人注意到他。

In the company, he was just a ___nonentity, unnoticed by anyone.

办公室里挤满了毫无存在感的员工，他们整天无所事事。

The office was filled with ___nonentities who did nothing productive all day.

在他的理论中，灵魂和鬼魂都只是不存在的虚幻概念。

In his theory, souls and ghosts are just ___nonentities with no real existence.