Found 2 items, similar to efficaciousness.
English → English (WordNet) Definition: efficaciousness efficaciousness n : capacity or power to produce a desired effect; “concern about the safety and efficacy of the vaccine” [syn: efficacy] [ant: inefficacy]
English → English (gcide) Definition: efficaciousness efficaciousness \ef`fi*ca"cious*ness\ n. the capacity or power to produce a desired effect. Syn: efficacy. [WordNet 1.5]