[ ih-fek-tiv-nis, ee-fek‐ ]
See synonyms for effectiveness on Thesaurus.com
  1. the quality of producing an intended or desired result: For maximum effectiveness of your weight loss plan, you need to combine exercise with a healthy diet.

  2. the quality of producing a deep or vivid impression: We were struck by the evident appeal and effectiveness of these short, dramatic, upbeat video stories.

  1. a measure of the success of a vaccine or other pharmaceutical when used in the real world, as opposed to the controlled environment of a clinical trial.: Compare efficacy (def. 2).

Origin of effectiveness

First recorded in 1600–10; effective + -ness
  • Rarely ef·fec·tiv·i·ty [ih-fek-tiv-i-tee, ee-fek-] /ɪˌfɛkˈtɪv ɪ ti, iˌfɛk-/ .

Other words from effectiveness

  • sub·ef·fec·tive·ness, noun
  • su·per·ef·fec·tive·ness, noun
  • un·ef·fec·tive·ness, noun

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use effectiveness in a sentence