This word is acceptable for play in the UK dictionary that is being used in the following games:

• Lexulous
• Wordscraper
• Wordosaur

To breathe or blow with a softly sibilant sound; whistle; hiss.

n. A sibilant râle. See râle.

"When their tread had died away from the ear, and the wind swept over the isolated grave with its customary siffle of indifference, Lot Swanhills turned and spoke to old Richard Toller, the hautboy player."