I forgot to mention that I agree with you that Elvish isn't a language. It is an adjective, as well as a noun used to refer to Elvish languages in general and Elvish writing systems. I can, however, answer your question about how to say "dog" in human. Well, there are countless languages used by humans, but one way to say it was already said by you: dog. Two other ways that I know how to say dog would be le chien (in French) and perro (in Spanish). Note that I didn't say "the French language".
Wait!!! Didn’t you understand me?
When I asked how to say dog in Human…I was actually meaning Bulgarian!!!!!
( As you can see by this example, saying Elvish is just as right as saying Human…can you identify the language? Is it a language after all?)