Depends what you want to say. 'Dead' is for things that have been alive at some point. A rock has never been alive, thus it cannot be dead. A rock is inanimate. But for a person or animal that is no longer living, then 'dead' is the adjective.

*inanimate: not living

It depends on the thing. It depends on what you mean. Tells us the actual thing you want to describe. The simplest is "dead." "Trees are alive, rocks are dead." For things made by human beings, one might choose different words. "Automobiles aren't alive, they are machines." "That Christmas tree isn't alive, it's artificial."

Tambien podras usar : objeto inanimado , o simplemente " inanimado

para mi la palabra seria : Cosa