Hwistlian

According to the Old English Dictionary:

hwistlian

p. ode To make a hissing sound, to hiss, whistle :-- Hé hwystlode stranglíc[e] stemne he [the devil] made a great hissing, Nar. 43, 17. [Wick. whistlen hiss (A. V.) Piers P. whistlen (to birds).]hwistlung, e; f. A hissing, WHISTLING, piping, music :-- Ðeós hwistlung hic sibilus, ðás hwystlunga hæc sibila, Ælfc. Gr. 13; Som. 16, 28. Hwistlung sibilatio, Ælfc. Gl. 79; Som. 72, 67; Wrt. Voc. 46, 24. Huislung simphonia, Lk. Skt. Lind. 15, 25. Ic beswíce fugelas mid hwistlunge decipio aves sibilo, Coll. Monast. Th. 25, 15. Suá suá mid líðre wisðlunga mon hors gestilleþ suá eác mid ðære illcan wistlunga mon mæg hund ástyrigean lenis sibilus equos mitigat, catulos instigat, Past. 23; Swt. 173, 21. hwistlian