We found 18 dictionaries that define the word mental deficiency:

General (11 matching dictionaries)

1. mental deficiency: Merriam-Webster
2. mental deficiency: Oxford Learner's Dictionaries
3. mental deficiency: American Heritage Dictionary of the English Language
4. mental deficiency: Collins English Dictionary
5. mental deficiency: Vocabulary.com
6. mental deficiency: Dictionary.com
7. Mental deficiency: Wikipedia, the Free Encyclopedia
8. mental deficiency: Rhymezone
9. mental deficiency: FreeDictionary.org
10. mental deficiency: Mnemonic Dictionary
11. mental deficiency: TheFreeDictionary.com

Business (3 matching dictionaries)

12. mental deficiency: Merriam-Webster Legal Dictionary
13. Glossary of Legal Terms (No longer online)
14. mental deficiency: Legal dictionary

Computing (1 matching dictionary)

15. mental deficiency: Encyclopedia

Medicine (3 matching dictionaries)

16. mental deficiency: Merriam-Webster Medical Dictionary
17. online medical dictionary (No longer online)
18. mental deficiency: Medical dictionary

Definitions from WordNet (mental deficiency) ▸ noun:  mild mental retardation Opposite: mental proficiency, mental ability, mental aptitude ▸ Words similar to mental deficiency ▸ Usage examples for mental deficiency ▸ Idioms related to mental deficiency ▸ Wikipedia articles (New!) ▸ Words that often appear near mental deficiency ▸ Rhymes of mental deficiency ▸ Invented words related to mental deficiency