efficiency /iˈfiʃənsi/ n. ［u］ 效率，功效：add efficiency to… 增加…的效率； develop efficiency 增进效率；improve/increase the efficiency of… 提高…的效率；raise labour efficiency 提高劳动效率；work efficiency 工作效率；the efficiency of investment 投资效益 The machine is not working at its highest efficiency. 这机器尚未发挥其最高效率。
efficient /iˈfiʃənt/ adj. 效率很高的，有能力：be fully efficient 充分发挥效率的 The diesel engine is highly efficient. 这种柴油机效率很高。A good manager is both competent and efficient. 一个好的管理者既有能力又有效率。
［辨析］见effective
