'Sibilate' definitions:

Definition of 'sibilate'

From: WordNet
verb
Pronounce with an initial sibilant
verb
Utter a sibilant
verb
Express or utter with a hiss [syn: hiss, sizz, siss, sibilate]
verb
Make a sharp hissing sound, as if to show disapproval [syn: hiss, siss, sizz, sibilate]

Definition of 'Sibilate'

From: GCIDE
  • Sibilate \Sib"i*late\, v. t. & i. To pronounce with a hissing sound, like that of the letter s; to mark with a character indicating such pronunciation. [1913 Webster]