|Definition - A consonant with a hissing sound, e.g. the /s/ in miss and the /z/ in his.|
Etymology - The term derives from the Latin sibilans, hissing (from sibilare, to hiss or whistle).
Oxford English Dictionary - Its first citation is from 1788:
"Next come different classes of dentals, and among the first of them should be placed the sibilants."
(W. Jones in Asiatick Researches I. 11)