No. If you use a word that says there is no god, or god is absent, you involved the concept of gods.<quoted text>Yes you can.
One small problem with your ascertaition: The word atheism, means without theism, or minus theism, or the lack of theism, or a complete dearth of theism. It means no theism. All are proper, in defining this word.
There is "no theism" in this connotation, it is lacking. The gods are neither there, nor not there in this application of word "atheism".
To say any element X does not exist employs the concept of X.
This is always true - by definition.