Main entry: inefficient
Definition: not producing desired results; wasteful
Usage: an inefficient campaign against drugs; outdated and inefficient design and methods
Antonyms: efficient
Definition: being effective without wasting time or effort or expense
Antonyms: thrifty
Definition: careful and diligent in the use of resources
Main entry: ineffective, inefficient
Definition: lacking the ability or skill to perform effectively; inadequate
Usage: an ineffective administration; inefficient workers
Antonyms: competent
Definition: properly or sufficiently qualified or capable or efficient
Antonyms: competent
Definition: legally qualified or sufficient