We found 34 dictionaries that define the word plethora:

General (26 matching dictionaries)

1. plethora: Merriam-Webster.com
2. plethora: Oxford Learner's Dictionaries
3. plethora: American Heritage Dictionary of the English Language
4. plethora: Collins English Dictionary
5. plethora: Vocabulary.com
6. Plethora, plethora: Wordnik
7. plethora: Cambridge Advanced Learner's Dictionary
8. plethora: Wiktionary
9. plethora: Webster's New World College Dictionary, 4th Ed.
10. plethora: The Wordsmyth English Dictionary-Thesaurus
11. plethora: Infoplease Dictionary
12. plethora: Dictionary.com
13. plethora: Online Etymology Dictionary
14. plethora: Cambridge Essential American English Dictionary
15. Plethora: Wikipedia, the Free Encyclopedia
16. Plethora: Online Plain Text English Dictionary
17. plethora: Webster's Revised Unabridged, 1913 Edition
18. plethora: Rhymezone
19. plethora: AllWords.com Multi-Lingual Dictionary
20. plethora: Webster's 1828 Dictionary
21. plethora: Free Dictionary
22. plethora: Mnemonic Dictionary
23. plethora: Dictionary/thesaurus
24. plethora: Wikimedia Commons US English Pronunciations

Business (1 matching dictionary)

25. plethora: Legal dictionary

Computing (1 matching dictionary)

26. plethora: Encyclopedia

Medicine (4 matching dictionaries)

27. Dorland's Illustrated Medical Dictionary (No longer online)
28. online medical dictionary (No longer online)
29. plethora: Medical dictionary
30. Rudy's List of Archaic Medical Terms (No longer online)

Miscellaneous (1 matching dictionary)

31. plethora: Wordcraft Dictionary

Slang (1 matching dictionary)

32. plethora: Urban Dictionary

(Note: See plethoras as well.)

Definitions from Wiktionary ( ) ▸ noun:  (usually followed by of) An excessive amount or number; an abundance. ▸ noun:  (medicine) Excess of blood in the skin, especially in the face and especially chronically. Similar: superfluity, nimiety, overplus, embarrassment, abundance, overquantity, plethory, plenteousness, plentitude, beaucoup, more... Opposite: dearth, scarcity, paucity Types: abundance, wealth, cornucopia, profusion, richness, copiousness, bountifulness, more... Phrases: a plethora, plethora of ivy, a plethora of, plethora of iy, plethora of, more... Adjectives: such, pulmonary, general, abdominal, whole, veritable, facial, hydremic, confusing, venous, current Colors:     crimson,     azure,     emerald,     amber,     violet, more... ▸ Word origin ▸ Words similar to plethora ▸ Usage examples for plethora ▸ Idioms related to plethora ▸ Wikipedia articles (New!) ▸ Popular adjectives describing plethora ▸ Words that often appear near plethora ▸ Rhymes of plethora ▸ Invented words related to plethora