The term 'sibilant' has two different senses or meanings: 1: of speech sounds produced by forcing air through a constricted passage (as `f', `s', `z', or `th' in both `thin' and `then'); 2: a...
According to the American Heritage Dictionary of the English Language, "sibilant" means:
"Of, characterized by, or producing a hissing sound like that of (s) or (sh): the sibilant consonants; a...