Hiss can be either a noun or a verb.
Noun: The hiss from the tape deck was very annoying.
Verb: The cat tends to hiss at anyone he doesn't recognize.
The plural of hiss is hisses, but it a word generally used as a verb rather than a noun.
It can be (hissing snakes, hissing cats). It is the present participle of the verb to hiss, and is otherwise a verb form or a noun (gerund).
alger hiss
The Hiss ended in 2008.
The Hiss was created in 2001.
Hiss
Hiss was a well-respected government offical.
Yes, they both hiss.
Mike Hiss was born in 1941.
Yehuda Hiss was born in 1946.
Alger Hiss
A hiss is a sibilant sound made by angry or frustrated animals.