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.
alger hiss
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).
The Hiss ended in 2008.
The Hiss was created in 2001.
Hiss
Mike Hiss was born in 1941.
Yehuda Hiss was born in 1946.
Yes, they both hiss.
Hiss was a well-respected government offical.
Alger Hiss
Yes. If you get close to them while they are nesting, they will hiss at you.