[1] : The Collaborative International Dictionary of English v.0.48

inefficient \in`effi"cient\, a.
   1. not efficient; not producing the effect intended or
      desired, or achieiving the effect by unnnecessary and
      excessive expenditure of resources; inefficacious; as,
      inefficient means or measures; inefficient methods are too
      expensive.
      1913 webster +pjc

   2. incapable of, or indisposed to, effective action;
      habitually slack or remiss; effecting little or nothing;
      as, inefficient workmen; an inefficient administrator.
      1913 webster

[2] : WordNet (r) 2.0

inefficient
     adj 1: not producing desired results; wasteful; "an inefficient
            campaign against drugs"; "outdated and inefficient
            design and methods" ant: efficient
     2: lacking the ability or skill to perform effectively;
        inadequate; "an ineffective administration"; "inefficient
        workers" syn: ineffective
see also:
efficient ineffective 

[3] : Moby Thesaurus II by Grady Ward, 1.0

42 moby thesaurus words for "inefficient":
   artless, careless, half-assed, inadept, inapt, inattentive,
   incapable, incapable of, incompetent, ineffective, ineffectual,
   inefficacious, inept, inexpert, inferior, mediocre, pedestrian,
   poor, skill-less, slipshod, slovenly, thoughtless, unable,
   unable to, unapt, undeft, undexterous, undextrous, unendowed,
   unfacile, unfit, unfitted, ungifted, unintelligent, unprepared,
   unproficient, unqualified, unskilled, unskillful, untalented,
   untrained, unworkmanlike

Inefficient >> I Words
Inefficient, definition of term: Inefficient
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