inefficient

Etymology

in- + efficient

adj

1. Not efficient; not producing the effect intended or desired; inefficacious
   Celery is an inefficient food.
2. Incapable of, or indisposed to, effective action; habitually slack or unproductive; effecting little or nothing
   The Defense Department, for example, has greatly expanded competitive bidding and is this year submitting to Congress the first-ever 2-year defense budget to replace the old, inefficient, year-by-year process. January 17 1987, Ronald Reagan, Presidential Radio Address
   inefficient workers
   an inefficient administrator
   Jessica was terribly inefficient at cleaning, so her brother usually had to clean the whole room.

noun

1. A person who cannot or does not work efficiently.
   Two men were put to work who could not set their looms; a third man was taken on who helped the inefficients to set the looms. The other weavers thought this was a breach of their union rules and 18 of them struck […] 1889, New York (State). Dept. of Labor. Bureau of Statistics, Annual Report (part 2, page 127)
   A general shaking up of the workers from top to bottom would result; and when equilibrium had been restored, the number of the inefficients at the bottom of the Abyss would have been increased by hundreds of thousands. 1903, Jack London, The People of the Abyss, Chapter 17