Sibilate is a verb meaning to make a hissing sound, similar to a WHISPER. It can be used to describe the sound of air escaping from a punctured tire or the sound of a snake. The crossword solutions for sibilate are SPIT (4 letters), FIZZ (4 letters), BUZZ (4 letters), WHEEZE (6 letters), SIZZLE (6 letters), WHISPER (7 letters), LISP (4 letters), and HISS (4 letters). All of these words describe sounds that are similar to a WHISPER, but with a more pronounced hissing quality.