We found 20 dictionaries that define the word photoperiodism:

General (12 matching dictionaries)

1. photoperiodism: Merriam-Webster
2. photoperiodism: Oxford Learner's Dictionaries
3. photoperiodism: American Heritage Dictionary of the English Language
4. photoperiodism: Collins English Dictionary
5. photoperiodism: Wordnik
6. photoperiodism: Wiktionary
7. photoperiodism: Webster's New World College Dictionary, 4th Ed.
8. photoperiodism: The Wordsmyth English Dictionary-Thesaurus
9. photoperiodism: Infoplease Dictionary
10. photoperiodism: Dictionary.com
11. Photoperiodism: Wikipedia, the Free Encyclopedia
12. photoperiodism: TheFreeDictionary.com

Computing (1 matching dictionary)

13. photoperiodism: Encyclopedia

Medicine (4 matching dictionaries)

14. photoperiodism: Merriam-Webster Medical Dictionary
15. Dorland's Illustrated Medical Dictionary (No longer online)
16. online medical dictionary (No longer online)
17. photoperiodism: Medical dictionary

Science (2 matching dictionaries)

18. Agricultural Thesaurus and Glossary (No longer online)
19. Bird On! (No longer online)

Tech (1 matching dictionary)

20. Glossary of Meteorology (No longer online)

Definitions from Wiktionary (photoperiodism) ▸ noun:  (biology) The growth, development and other responses of plants and animals according to the length of day and/or night. Similar: photoperiod, daylength, photoperiodicity, thermoperiod, bioperiodicity, photoregime, scotoperiod, phenology, photomorphogenesis, phenometry, more... Opposite: scotoperiodism, nyctiperiodism ▸ Words similar to photoperiodism ▸ Usage examples for photoperiodism ▸ Idioms related to photoperiodism ▸ Wikipedia articles (New!) ▸ Popular adjectives describing photoperiodism ▸ Words that often appear near photoperiodism ▸ Rhymes of photoperiodism ▸ Invented words related to photoperiodism