Synonyms for efficiency

noun

1. A high degree of effectiveness

   competence, capability, capableness; see ability 2.

2. The relation of results to expenditure

   productivity, effectiveness, power, potency, performance, suitability, adaptability, thoroughness, energy, effectualness, efficaciousness, adequacy, productiveness, powerfulness, efficacy, competence, proficiency, elasticity, conductivity, response, potential energy, faculty, facility, practical utility, profitability, yield.