We found 23 dictionaries that define the word flash flood:

General (18 matching dictionaries)

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

Computing (1 matching dictionary)

17. flash flood: Encyclopedia

Science (1 matching dictionary)

18. Illustrated Glossary of Geologic Terms (No longer online)

Slang (1 matching dictionary)

19. Flash flood: Urban Dictionary

Tech (2 matching dictionaries)

20. Glossary of Meteorology (No longer online)
21. National Weather Service Glossary (No longer online)

(Note: See flash_flooding as well.)

Definitions from Wiktionary (flash flood) ▸ noun:  (meteorology) A sudden, rapid flood, usually of short duration and local impact. Similar: flashflood, flood, sky-flood, freshet, floodlet, flunami, flit, floodflow, floodtime, floodwater, more... Opposite: drought, dry spell, aridity Types: river flood, urbflood, storm surge, mudflow, more... Phrases: Flash flood warning, more... Adjectives: bomb, stormy, inch, weather, stormie, hail, complex, pat, tornadic, stormful, fresh ▸ Words similar to flash flood ▸ Usage examples for flash flood ▸ Idioms related to flash flood ▸ Wikipedia articles (New!) ▸ Words that often appear near flash flood ▸ Rhymes of flash flood ▸ Invented words related to flash flood