Meaning

noun the sound made by something moving rapidly or by steam coming out of a small aperture

noun the act of signalling (e.g., summoning) by whistling or blowing a whistle

noun a small wind instrument that produces a whistling sound by blowing into it

originFrom Middle English whistlen, from Old English hwistlan, hwistlian (“to whistle”), from Proto-West Germanic *hwistlōn, from Proto-Germanic *hwistlōną (“to make a hissing sound”). Cognate with Swedish vissla (“to whistle”), Icelandic hvísla (“to whisper”), Russian свистеть (svistetʹ, “to whistle”).

Etymology from Wiktionary, CC BY-SA 3.0