We found 23 dictionaries that define the word nuclear winter:

General (18 matching dictionaries)

1. nuclear winter: Merriam-Webster
2. nuclear winter: Oxford Learner's Dictionaries
3. nuclear winter: American Heritage Dictionary of the English Language
4. nuclear winter: Collins English Dictionary
5. nuclear winter: Vocabulary.com
6. nuclear winter: Wordnik
7. nuclear winter: Cambridge Advanced Learner's Dictionary
8. nuclear winter: Wiktionary
9. nuclear winter: The Wordsmyth English Dictionary-Thesaurus
10. nuclear winter: Infoplease Dictionary
11. nuclear winter: Dictionary.com
12. Nuclear Winter, Nuclear winter (disambiguation), Nuclear winter: Wikipedia, the Free Encyclopedia
13. nuclear winter: Rhymezone
14. nuclear winter: FreeDictionary.org
15. nuclear winter: Mnemonic Dictionary
16. nuclear winter: TheFreeDictionary.com

Computing (1 matching dictionary)

17. nuclear winter: Encyclopedia

Science (1 matching dictionary)

18. Atmospheric Chemistry and Air Quality (No longer online)

Slang (1 matching dictionary)

19. nuclear winter: Urban Dictionary

Tech (2 matching dictionaries)

20. Glossary of Meteorology (No longer online)
21. Explosives (No longer online)

(Note: See nuclear_winters as well.)

Definitions from Wiktionary (nuclear winter) ▸ noun:  A predicted drop in global temperature following a nuclear war due to dust in the upper atmosphere reducing sunlight reaching the ground. Similar: volcanic winter, snowout, impact winter, termination dust, cold spell, ground frost, winter storm, freeze, freeze-up, sudden stratospheric warming, more... Opposite: nuclear summer, nuclear spring, nuclear thaw Types: global cooling, nuclear twilight, nuclear night, more... Adjectives: hydroelectric, hydro, hydro-electric, turboelectric, online, sub-zero, centigrade, power, amped, ultracold, indirect ▸ Words similar to nuclear winter ▸ Usage examples for nuclear winter ▸ Idioms related to nuclear winter ▸ Wikipedia articles (New!) ▸ Words that often appear near nuclear winter ▸ Rhymes of nuclear winter ▸ Invented words related to nuclear winter