whistling in WordNet English dictionary

1. the act of signalling (e.g., summoning) by whistling or blowing a whistle
   "the whistle signalled the end of the game"
   whistle  whistling 
   
2. the sound made by something moving rapidly or by steam coming out of a small aperture
   whistle  whistling 
   
3. the act of whistling a tune
   "his cheerful whistling indicated that he enjoyed his work"
   whistling