a. having no beneficial use or incapable of functioning usefully
a. 无用的, 无效的, 无益的
[机] 无用, 无价值, 无效
1. This tool is useless for fixing the car.
这个工具对修车没有用。
2. He felt useless after losing his job.
失去工作后，他感到自己毫无用处。
3. The instructions were so unclear that they seemed useless.
这些说明书模糊不清，似乎没有任何用处。