We found 27 dictionaries that define the word phytoplankton:

General (16 matching dictionaries)

1. phytoplankton: Merriam-Webster
2. phytoplankton: Oxford Learner's Dictionaries
3. phytoplankton: American Heritage Dictionary of the English Language
4. phytoplankton: Collins English Dictionary
5. phytoplankton: Vocabulary.com
6. Phytoplankton, phytoplankton: Wordnik
7. phytoplankton: Wiktionary
8. phytoplankton: Webster's New World College Dictionary, 4th Ed.
9. phytoplankton: The Wordsmyth English Dictionary-Thesaurus
10. phytoplankton: Infoplease Dictionary
11. phytoplankton: Dictionary.com
12. Phytoplankton: Wikipedia, the Free Encyclopedia
13. phytoplankton: Rhymezone
14. phytoplankton: FreeDictionary.org
15. phytoplankton: Mnemonic Dictionary
16. phytoplankton: TheFreeDictionary.com

Computing (1 matching dictionary)

17. phytoplankton: Encyclopedia

Medicine (3 matching dictionaries)

18. Medical Dictionary (No longer online)
19. online medical dictionary (No longer online)
20. phytoplankton: Medical dictionary

Science (5 matching dictionaries)

21. Agricultural Thesaurus and Glossary (No longer online)
22. Botanical Terms (No longer online)
23. On-Line Biology Book: GLOSSARY (No longer online)
24. phytoplankton: Evolution Glossary
25. phytoplankton: Natural History Terms

Tech (2 matching dictionaries)

26. Lake and Water Word Glossary (No longer online)
27. Glossary of Water Resource Terms (No longer online)

(Note: See phytoplanktonic as well.)

Definitions from Wiktionary (phytoplankton) ▸ noun:  Plankton, especially those small in size, that obtain energy by photosynthesis. Similar: microplankton, meroplankton, zooplankton, megaplankton, plankton, macroplankton, mesoplankton, microzooplankton, planktonivore, euplankton, more... Opposite: zooplankton, microzooplankton, macrozooplankton Phrases: phytoplankton bloom, more... Adjectives: marine, freshwater, natural, oceanic, net, total, small, toxic, microscopic, larger, coastal Colors:     green,     blue,     cyan,     teal,     turquoise, more... ▸ Words similar to phytoplankton ▸ Usage examples for phytoplankton ▸ Idioms related to phytoplankton ▸ Wikipedia articles (New!) ▸ Popular adjectives describing phytoplankton ▸ Words that often appear near phytoplankton ▸ Rhymes of phytoplankton ▸ Invented words related to phytoplankton