verb/si.fle/
to whistle; to whistle for, to blow on a whistle for; to boo by whistling (to show one's disapproval at something); to hiss; to knock back (a drink), to down
“Il siffle un air bizarre.” — He's whistling a strange tune.
Inherited from Old French sifler (later orthographically influenced by souffler), from Vulgar Latin *sīfilāre, probably an Osco-Umbrian influenced variant of Latin sībilāre (compare Spanish chiflar, Friulian sivilâ). Compare also the variant northern Old French dialectal form sufler (whence Norman sûfflier and Walloon xhufler), from a Vulgar Latin variant *sufilāre (compare Italian zufolare), as well as the dialectal subler from a form *subilāre (compare Italian sobillare, Romansh tschüblar, Rom