Why is a chair called a chair?

Have you ever wondered why a computer is called computer? Or why a chair is called a chair? I have. And I also wonder who decided to call that particular object (or activity) a chair, or a computer. I still don’t know.

Well, I know how some objects got their name. They’re just named after the inventor’s name. Like a zeppelin, that is named after Ferdinand von Zeppelin.

Those things are called eponyms. 

ep·o·nym ( p -n m )

n.

1. A word or name derived from the name of a person. The words atlas, bowdlerize, and Turing machine are eponyms.

2. A person whose name is or is thought to be the source of the name of something.

But that still doesn’t answer my questions. Because not all things are named after a person. Was there just someone who said ‘mmm let’s call it a chair!’? And then think of all the different languages that use a different word for the same object. I guess I will never know, because it goes way back. For now I just assume that an inventor has named his invention or after his own name, or just thought of a fictive name.