usefulness

名词 usefulness:

1. the quality of being of practical use
   同义词：utility

1. Consider the postage stamp: its usefulness consist in the ability to stick to one thing till it get there.
   想想那邮票吧：其用处在于它能粘住一样东西直至达到目的为止。
2. A regulation that has outlived its usefulness.
   已经没用却仍然存在的规则
3. When he retired he felt that he had outlived his usefulness.
   他退休后觉得自己年老无用了。
4. Impairment of the usefulness or value of person or property; harm.
   损害，破坏对有用或有价值的人或财产的破坏; 伤害