efficacy
noun [ U ] uk/ˈef.ɪ.kə.si/ us/ˈef.ə.kə.si/
formal功效，效力，效验
the ability, especially of a medicine or a method of achieving something, to produce the intended result
They recently ran a series of tests to measure the efficacy of the drug. 他们最近进行了一系列的试验来检测这种药的功效。
Synonym: effectiveness