noun
1.
the capacity to produce desired results with a minimum expenditure of energy, time, or resources
demands a high degree of efficiency on the job
Synonyms: effectiveness, efficacy, performance
Related Word: ability, address, adeptness, competence, expertise, know-how, proficiency, prowess, skill; capability, resourcefulness; productivity
Contrasted words: inadequacy, incompetence, ineffectiveness; unproductiveness
Antonyms: inefficiency
2.
Synonyms: efficacy 1, capability, effectiveness, potency