We found 9 dictionaries that define the word warning signal:

General (6 matching dictionaries)

1. warning signal: Vocabulary.com
2. warning signal: Dictionary.com
3. warning signal: Rhymezone
4. warning signal: FreeDictionary.org
5. warning signal: Mnemonic Dictionary
6. warning signal: TheFreeDictionary.com

Computing (1 matching dictionary)

7. warning signal: Encyclopedia

Tech (2 matching dictionaries)

8. AUTOMOTIVE TERMS (No longer online)
9. Explosives (No longer online)

(Note: See warning_signals as well.)

Definitions from WordNet (warning signal) ▸ noun:  an automatic signal (usually a sound) warning of danger ▸ Words similar to warning signal ▸ Usage examples for warning signal ▸ Idioms related to warning signal ▸ Wikipedia articles (New!) ▸ Words that often appear near warning signal ▸ Rhymes of warning signal ▸ Invented words related to warning signal