Definitions

1. adjective

Hissing or producing a hissing sound; having a sharp, high-pitched sound, like the sound of the letter ‘s’ when pronounced.

“The sibilous wind whistled through the desolate landscape.”

2. noun

A person who is fond of or given to hissing or making sibilant sounds, especially in criticism or disapproval.

“The sibilous critic panned the play for its poor acting and weak plot.”