noun, masculine/si.flə.mɑ̃/plural: sifflements
a whistling (action); whistle (sound); various hissing noises such as produced by a gush of wind, a diving bird or an air-piercing arrow (see sifflant).; noises produced by certain animals resembling a whistling, said of snakes, marmots, or cats.
From siffler + -ment.