We found 34 dictionaries that define the word effectiveness:

General (20 matching dictionaries)

1. effectiveness: Merriam-Webster
2. effectiveness: Oxford Learner's Dictionaries
3. effectiveness: Collins English Dictionary
4. effectiveness: Vocabulary.com
5. Effectiveness, effectiveness: Wordnik
6. effectiveness: Cambridge Advanced Learner's Dictionary
7. effectiveness: Wiktionary
8. Effectiveness, effectiveness: Dictionary.com
9. effectiveness: Cambridge Essential American English Dictionary
10. Effectiveness: Wikipedia, the Free Encyclopedia
11. Effectiveness: Online Plain Text English Dictionary
12. effectiveness: Webster's Revised Unabridged, 1913 Edition
13. effectiveness: Rhymezone
14. Effectiveness: AllWords.com Multi-Lingual Dictionary
15. effectiveness: FreeDictionary.org
16. effectiveness: Mnemonic Dictionary
17. effectiveness: TheFreeDictionary.com
18. effectiveness: Wikimedia Commons US English Pronunciations

Business (3 matching dictionaries)

19. effectiveness: Merriam-Webster Legal Dictionary
20. effectiveness: Legal dictionary
21. BusinessDictionary.com (No longer online)

Computing (2 matching dictionaries)

22. Effectiveness: Cybernetics and Systems
23. effectiveness: Encyclopedia

Medicine (8 matching dictionaries)

24. effectiveness: Merriam-Webster Medical Dictionary
25. Dorland's Illustrated Medical Dictionary (No longer online)
26. AIDSinfo Glossary (No longer online)
27. online medical dictionary (No longer online)
28. GI Disorders (No longer online)
29. Effectiveness: Glossary of Medical Education Terms
30. AIDS Medical Glossary and Drug Chart (No longer online)
31. effectiveness: Medical dictionary

Miscellaneous (1 matching dictionary)

32. A Brief Critical Dictionary of Education (No longer online)

(Note: See effective as well.)

Definitions from Wiktionary (effectiveness) ▸ noun:  The property of being effective, of achieving results. ▸ noun:  The capacity or potential for achieving results. ▸ noun:  The degree to which something achieves results. Similar: effectuality, potency, strength, efficacy, usefulness, efficiency, ineffectiveness, efficaciousness, successfulness, affectiveness, more... Opposite: inefficiency, ineffectiveness, uselessness, futility, incompetence Types: placebo, placebo effect, nocebo, nocebo effect, therapeutic, therapeutic effect, placebo response, more... Phrases: cost effectiveness, comparative effectiveness, precipitation effectiveness, Relative biological effectiveness, cost effectiveness analysis, more... Adjectives: cost, relative, organizational, overall, greatest, maximum, clinical, therapeutic, potential, military, term Colors:     blue,     green,     teal,     turquoise,     emerald, more... ▸ Words similar to effectiveness ▸ Usage examples for effectiveness ▸ Idioms related to effectiveness ▸ Wikipedia articles (New!) ▸ Popular adjectives describing effectiveness ▸ Words that often appear near effectiveness ▸ Rhymes of effectiveness ▸ Invented words related to effectiveness