Sibilation
Pronunciation : Sib`i*la"tion
Part of Speech : n.
Etymology : [L. sibilatio.]
Definition : Defn: Utterance with a hissing sound; also, the sound itself; a hiss. He, with a long, low sibilation, stared. Tennyson.
Source : Webster's Unabridged Dictionary, 1913
Merriam-Webster's Everyday Language Reference Set: Includes: The Merriam-Webster Dictionary, The Merriam-Webster Thesaurus, and The Merriam-Webster Vocabulary Builder