1) Sound 2) The act of whistling a tune 3) Vocal skill 4) Whistle 1) Whistle 
Whistling is the production of sound by means of carefully controlling a stream of air flowing through a small hole. Whistling can be achieved by creating a small opening with one`s lips and then blowing or sucking air through the hole. The air is moderated by the lips, tongue, teeth or fingers (placed over the mouth) to create turbulence, and th....
• a. & n. from Whistle, v. • (p. pr. & vb. n.) of Whistle
Whistling in dressing rooms is traditionally considered bad luck. To appease the gods you must turn around three times, leave the room for a minute, then knock three times and re-enter! 
Whis'tling adjective & noun from Whistle , v. Whistling buoy . (Nautical) See under Buoy . -- Whistling coot (Zoology) , the American black scoter. -- Whistling Dick . (Zoology) (a) 
[n] - the act of whistling a tune
noun the act of whistling a tune; `his cheerful whistling indicated that he enjoyed his work`