We found 19 dictionaries that define the word yellow flag:

General (11 matching dictionaries)

1. yellow flag: Oxford Learner's Dictionaries
2. yellow flag: Collins English Dictionary
3. yellow flag: Vocabulary.com
4. yellow-flag, yellow flag: Wordnik
5. yellow flag: Wiktionary
6. yellow flag: Dictionary.com
7. The Yellow Flag, Yellow flag (contagion), Yellow flag: Wikipedia, the Free Encyclopedia
8. yellow flag: Rhymezone
9. yellow flag: FreeDictionary.org
10. yellow flag: Mnemonic Dictionary
11. yellow flag: TheFreeDictionary.com

Medicine (2 matching dictionaries)

12. yellow flag: Merriam-Webster Medical Dictionary
13. yellow flag: Medical dictionary

Science (2 matching dictionaries)

14. Yellow Flag: Botanical Name listing of Plants
15. A Modern Herbal, 1931, by Mrs. M. Grieve (No longer online)

Slang (1 matching dictionary)

16. yellow flag: Urban Dictionary

Sports (2 matching dictionaries)

17. Hickok Sports Glossaries (No longer online)
18. Yellow flag: Sports Definitions

Tech (1 matching dictionary)

19. AUTOMOTIVE TERMS (No longer online)

(Note: See yellow_flags as well.)

Definitions from Wiktionary (yellow flag) ▸ noun:  A Eurasian and northwest-African aquatic iris, Iris pseudacorus. ▸ noun:  Used other than figuratively or idiomatically: see yellow, flag. Similar: Iris pseudacorus, yellow iris, yellow water flag, water flag, sword-flag, flag, Siberian flag, Spanish iris, iris, Siberian iris, more... Opposite: green flag, go signal, all clear Phrases: yellow water flag, more... ▸ Words similar to yellow flag ▸ Usage examples for yellow flag ▸ Idioms related to yellow flag ▸ Wikipedia articles (New!) ▸ Words that often appear near yellow flag ▸ Rhymes of yellow flag ▸ Invented words related to yellow flag