We found 17 dictionaries that define the word harmfulness:

General (13 matching dictionaries)

1. harmfulness: Merriam-Webster
2. harmfulness: Oxford Learner's Dictionaries
3. harmfulness: Collins English Dictionary
4. harmfulness: Vocabulary.com
5. harmfulness: Wordnik
6. harmfulness: Cambridge Advanced Learner's Dictionary
7. harmfulness: Wiktionary
8. harmfulness: Dictionary.com
9. harmfulness: Rhymezone
10. harmfulness: Webster's 1828 Dictionary
11. harmfulness: FreeDictionary.org
12. harmfulness: Mnemonic Dictionary
13. harmfulness: TheFreeDictionary.com

Business (2 matching dictionaries)

14. harmfulness: Merriam-Webster Legal Dictionary
15. harmfulness: Legal dictionary

Computing (1 matching dictionary)

16. harmfulness: Encyclopedia

Medicine (1 matching dictionary)

17. harmfulness: Medical dictionary

(Note: See harmful as well.)

Definitions from Wiktionary (harmfulness) ▸ noun:  The characteristic of being harmful. Similar: noxiousness, noisomeness, injuriousness, harmlessness, unharmfulness, abusefulness, hurtfulness, detrimentalness, deleteriousness, hatefulness, more... Opposite: beneficence, helpfulness, benignancy ▸ Words similar to harmfulness ▸ Usage examples for harmfulness ▸ Idioms related to harmfulness ▸ Wikipedia articles (New!) ▸ Popular adjectives describing harmfulness ▸ Words that often appear near harmfulness ▸ Rhymes of harmfulness ▸ Invented words related to harmfulness