whistle
noun
[ ˈwɪs(ə)l ]
• a clear, high-pitched sound made by forcing breath through a small hole between partly closed lips, or between one's teeth.
• a suit.
whistle
verb
• emit a clear, high-pitched sound by forcing breath through a small hole between one's lips or teeth.
• "the audience cheered and whistled"
Origin:
Old English (h)wistlian (verb), (h)wistle (noun), of Germanic origin; imitative and related to Swedish vissla ‘to whistle’.