WWordGenerator.org GeneratorsWord ListsBlogAboutGenerate a word Home / E / efficaciousness efficaciousness noun /ɛfəkeɪʃəsnɛs/ 5 syllables 15 letters Scrabble 25 WWF 29 Definitions noun capacity or power to produce a desired effect efficacy Look “efficaciousness” up elsewhere Wiktionary ↗ Merriam-Webster ↗ Etymonline ↗ Dictionary.com ↗ Want another word?Spin the dictionary for a fresh one. Generate a word →