SISS
hiss, siss, sizz, sibilate
(verb) make a sharp hissing sound, as if to show disapproval
hiss, sizz, siss, sibilate
(verb) express or utter with a hiss
Source: WordNet® 3.1
Etymology
Noun
siss (plural sisses)
(US, colloquial) A hissing noise.
Verb
siss (third-person singular simple present sisses, present participle sissing, simple past and past participle sissed)
(US, colloquial, intransitive) To make a hissing sound.
Anagrams
• SSIS, SSIs, SSSI
Source: Wiktionary
Siss, v. i. Etym: [Of imitative origin; cf. D. sissen, G. zischen.]
Definition: To make a hissing sound; as, a flatiron hot enough to siss when
touched with a wet finger. [Colloq. U. S.; Local, Eng.]
Siss, n.
Definition: A hissing noise. [Colloq. U. S.]
Source: Webster’s Unabridged Dictionary 1913 Edition