We found 27 dictionaries that define the word efficacious:

General (24 matching dictionaries)

1. efficacious: Merriam-Webster
2. efficacious: Oxford Learner's Dictionaries
3. efficacious: American Heritage Dictionary of the English Language
4. efficacious: Collins English Dictionary
5. efficacious: Vocabulary.com
6. Efficacious, efficacious: Wordnik
7. efficacious: Cambridge Advanced Learner's Dictionary
8. efficacious: Wiktionary
9. efficacious: Webster's New World College Dictionary, 4th Ed.
10. efficacious: The Wordsmyth English Dictionary-Thesaurus
11. efficacious: Infoplease Dictionary
12. Efficacious, efficacious: Dictionary.com
13. Efficacious: Wikipedia, the Free Encyclopedia
14. Efficacious: Online Plain Text English Dictionary
15. efficacious: Webster's Revised Unabridged, 1913 Edition
16. efficacious: Rhymezone
17. Efficacious: AllWords.com Multi-Lingual Dictionary
18. efficacious: Webster's 1828 Dictionary
19. efficacious: FreeDictionary.org
20. efficacious: Mnemonic Dictionary
21. efficacious: TheFreeDictionary.com
22. efficacious: Longman Dictionary of Contemporary English

Business (1 matching dictionary)

23. efficacious: Legal dictionary

Computing (1 matching dictionary)

24. efficacious: Encyclopedia

Medicine (1 matching dictionary)

25. efficacious: Medical dictionary

(Note: See efficaciously as well.)

Definitions from Wiktionary ( ) ▸ adjective:  (formal) Effective; possessing efficacy. Similar: effective, effectual, telling, impressive, hard-hitting, trenchant, impelling, effectatious, efficious, efficient, more... Opposite: ineffective, inefficacious, unsuccessful, unproductive, useless Types: placebo, placebo effect, nocebo, nocebo effect, placebo response, nocebo response, more... Phrases: efficacious remedy, more... ▸ Words similar to efficacious ▸ Usage examples for efficacious ▸ Idioms related to efficacious ▸ Wikipedia articles (New!) ▸ Popular nouns described by efficacious ▸ Words that often appear near efficacious ▸ Rhymes of efficacious ▸ Invented words related to efficacious