We found 25 dictionaries that define the word whistling:

General (20 matching dictionaries)

1. whistling: Merriam-Webster
2. whistling: Collins English Dictionary
3. whistling: Vocabulary.com
4. Whistling, whistling: Wordnik
5. whistling: Cambridge Advanced Learner's Dictionary
6. whistling: Wiktionary
7. whistling: Webster's New World College Dictionary, 4th Ed.
8. whistling: Infoplease Dictionary
9. whistling: Dictionary.com
10. whistling: Cambridge Essential American English Dictionary
11. Whistling: Wikipedia, the Free Encyclopedia
12. Whistling: Online Plain Text English Dictionary
13. whistling: Webster's Revised Unabridged, 1913 Edition
14. whistling: Rhymezone
15. Whistling: AllWords.com Multi-Lingual Dictionary
16. whistling: Webster's 1828 Dictionary
17. Whistling: E Cobham Brewer, The Reader's Handbook
18. whistling: FreeDictionary.org
19. whistling: Mnemonic Dictionary
20. whistling: TheFreeDictionary.com

Computing (1 matching dictionary)

21. whistling: Encyclopedia

Medicine (1 matching dictionary)

22. Whistling (theatre), whistling: Medical dictionary

Miscellaneous (2 matching dictionaries)

23. Encyclopedia of Graphic Symbols (No longer online)
24. whistling: Idioms

Slang (1 matching dictionary)

25. Whistling: Urban Dictionary

(Note: See whistle as well.)

Definitions from Wiktionary (whistling) ▸ noun:  A shrill, breathy sound; a whistle. Similar: whiff, shrilling, whiffling, whirring, wheeze, whing, whiz, whisperingness, death whistle, whickering, more... Opposite: silence, quiet, mute Types: pitch, tone, siren, whine, wail, scream, hiss, buzz, more... Phrases: whistling swan, whistling swans, whistling duck, whistling ducks, whistling dixie, more... Adjectives: shrill, loud, soft, low, sharp, faint, cheerful, peculiar, much, constant, tuneless Colors:     sky blue,     mint green,     silver,     pale yellow,     lavender, more... ▸ Words similar to whistling ▸ Usage examples for whistling ▸ Idioms related to whistling ▸ Wikipedia articles (New!) ▸ Popular adjectives describing whistling ▸ Words that often appear near whistling ▸ Rhymes of whistling ▸ Invented words related to whistling