whistling

noun

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

Also useful for “whistling”:Unscrambler— Rearrange the letters in “whistling”