无用功

無用功
wúyònggōng

useless work; ineffective work

Wiktionary

Entry Composition

1 无用 wúyòng
  1. useless
  2. worthless
2 功 gōng
  1. meritorious deed or service
  2. achievement
  3. result
  4. service
  5. accomplishment
  6. work (physics)