Definition of effectualness in US English:

effectualness

noun

  • See effectual

    • ‘Once the effectualness of these principles is realized, it's hard to fathom working any other way, and it's really very simple.’
    • ‘It's been proven by numerous patients for years but late analyses have disputed the effectualness of these drugs.’

Pronunciation

effectualness

/əˈfɛk(t)ʃ(u)əlnəs//əˈfek(t)SH(o͞o)əlnəs/