hiss (n.) Look up hiss at Dictionary.com
"a continued 's' sound, commonly expressing disapproval or contempt," 1510s, from hiss (v.).
hiss (v.) Look up hiss at Dictionary.com
late 14c., of imitative origin. Compare Danish hysse, German zischen, etc. Johnson wrote, "it is remarkable, that this word cannot be pronounced without making the noise which it signifies." Related: Hissed; hissing.